TLDR in the bottom.
Disclaimer: I agree that the Golden Age 1989-2005 is unsurpassed in terms of hit games per year and innovation. I loved alot of games during that era and played them when they came out and have the game boxes at my dads attic: Morrowind, Shogun: Total War, Warcraft 2-3, Starcraft, Silver, Atlantis, Commandos, Homeworld, Lords of the realm 2, Black & White, Outcast, MoH&CoD, Xwing vs Tie, Diablo 1-2, Settlers 2, Tachyon: the Fringe, Freespace 1-2, Ground Control 1, DoW1, Monkey Island 3, Dungeon Keeper, Hearts of Iron, Hexen 1-2, Heretic 1-2, Quake 1-2, Future Cop LAPD, Half Life 1-2 etc etc. And earlier I played a lot of Amiga 500 and Nintendo 8. Honorable mention to the mod The Specialist for HL1, unsurpassed pvp twitch shooter.
Advancements in recent gaming:
With that said alot of my favorite games has been made after 2005. Advancement in immersion, online play, hardware and innovation made these possible. The RTS genre while not as vast as before has been refined. There are a lot of games that are if not outright innovative but atleast evolutionary and that is incline. Sure the classics are excellent, but these newer games have improvements that wins me over if I'm looking to play something.
RTS & RTT:
Dawn Of War 2: It has a good story with strong classic mission with several objectives, especially Chaos Rising. But it really shines in multiplayer, especially Retribution. I have poured hundred of hours playing these games online. The tech allows good progression in multiplayer and team games becomes epic army battles. Good evolutionary combination of classic rts with rtt and warcraft 3 style heroes that carries over in campaigns. It's focus on RTT makes it a difference game than DoW1, especially campaign (that you can play coop).
Wargame series: Pinnacle of RTT PvP online gaming. Big maps that forces the player to think about road speed, fuel, ammo and time until reinforcements. Good deck system to customize your force. Very complex unit interactions: motorised or mechanized units armour and firepower vs speed, helicopters all from transport and supply to recon and attack helicopters. Anti air, both optical and radar, gun and missile. Sense anti radar missiles ( SEAD ) exists radar aa can become a liability. Tanks, special forces Recon, ATGMs, scouts, jets etc etc. Hundreds of hours on these games.
WARNO: This is still in early access but is becoming a true evolution of the series. Eugen Systems are implementing new mechanics like smart orders and Rules of Engagement(no more dumb robots as soldiers, you can set them to retreat or advance when taking fire), better urban areas including high rises, actively working against cheese by fixing helicopters and improving systems like sight, rebalancing turn speed of tank turret to balance forest engagement vs infantry etc etc, faster ATGMs that can retarget, trait system, reworked fobs, smoke launchers for vehicles, SEAD planes that actually jams radar aa, divisions, can give orders before battle starts. Several QoL improvements combined with actual new mechanics and active development could make this game an instant classic when they finish with it. Nothing this complex in real time had been released before.
Supreme Commander: Sure a spiritual succesor to TA. But again hardware capabilities of the 00s and 10s allowed games to take advantage of these and transform them into gameplay mechanics. The scale and zoom of supcom is truly massive and the interface was reworked so you can flawlessly at a glance get the information you require. Nostalgia or no, SupCom was a technical evolution of the subgenre made possible through harnessing hardware advancement. Just like 3D games of the 90s were made passible through harnessing new hardware. Maybe not an innovation but atleast an evolution.
Online play:
Insurgency mod for HL2: Slow paced tactical pvp with precise character control in small maps where people actually go down when you hit them, one of the best pvp shooters where slow smart movement is rewarded. Nothing like it before.
Project Reality Battlefield 2 mod: V1.0 released 2013. Made BF2 into an actual semi mil pvp shooter that promoted teamplay. Big maps. Sure BF 1942 and Operation Flashpoint was earlier but they respectively did not have the realism or frequent massive pvp games where people cooperated. One of the best games ever released, with Squad making a good effort to catch up now with it's Infantry Combat Overhaul project. Separate gunner driver, mortar, atgm placements, only spawn in main base, fobs or squad rally points. etc etc.
Empires mod for HL2: A multiplayer Battlezone game where your team form in squads and have to secure refineries over big maps. But one player on each team plays as a commander that can place down buildings like barracks and factories, making close teamplay between squads and the command a necessity to win or even play the game. The commander also choses research that affects vehicles that goes from apc, light to heavy tank and mobile artillery. For example electrical gives faster vehicles, physic harder, bio give DOT damage etc etc. Lots of fun stuff, engineers can build walls, gun/missle towers and ammo caches with seismic grenades. Riflemen got assault carbine or MG, scouts with invis. Could develop into fun ww1 battles from time to time but also massive coordinated mechanized assaults. One of the best multiplayer pvp "massive" team game of all time, a truly innovative and experimental game, it even had a "invasion" mode that was purely tactical and fun.
Age of Chivalry mod for HL2: First person pvp mayhem with close combat weapons, nothing like it had came before that was played at that scale, hundreds of hours of fun with 32vs32. It basically created a new genre even if small with Mordhau vs Chivalry 2 are the current ones.
Game mechanics:
Dark Souls 1: Need no introduction, excellent world building and lore. But I don't agree that it is a Ninja Garden style game, maybe Elden Ring and DS3 is but not DS1 and 2. What made DS1 so special for me was that the character was slow. It allowed every weapon to truly show of its unique capability. Fighting with a halberd, spear, two handed sword or a short sword gave complexly different play styles, and the character was not jumping around the whole screen like an anime character like in Ninja Garden. A souls like for me must have weight and momentum to the character and it's weapons with locked in animations, overwise it's just a Devil May Cry game.
Dark Souls 2: Many don't like it as much but for me it's a gem. The unique things about DS2 it that it makes the story personal, not about gods, but the intro cutscenes is about your actual character seeing his friends and family slipping away, losing his mind. The intro with the witches in the dark forest with 5.1 at night almost turns the game into a horror game, excellent suspense and later on the setting is part wise best of the franchise.
Dark Souls 3: Adds fluid mechanics, good vistas, good bosses, better magic & weapon art system and most of all an actual good endgame section, even more so with its DLCs. Good pvp.
Disco Elysium: One of the best rpgs that is actual innovative by giving the attributes voices combined with a faster dialog doing away with the lore dump "conversations" of the infinity engines games. Beautiful setting and you really feel for the character. Good cast and score.
Immersion open world games:
Death Stranding: A game that manages to transform walking from a timesink to an actual engaging experience and did so over beautiful diverse terrain and did so with a gameplay mechanics that support the story and game loop, you really want to build up the roads. Along the asynchronous multiplayer the core gameplay loop was really fun for me, good combination of building and hiking. I spend a lot of time building up a zipline network in the mountain that cut travel time down to nothing once it was complete, pioneer feeling. An innovative game, even if you don't like it.
ELEX: Big beautifully open world with diverse biomes to explore easily with the jetpack. Excellent quest design and characters. I was completely hooked playing this game from start to finish. One of the few games that really made me comeback for more until I finish the whole game, played it with an overhaul mod ofcourse. Devs can never balance for shit no matter the game or company.
Risen 1: Excellent combination of medieval people on Caribbean island, the intro is really immerse with the dark thunderstorm on the beach.
Red Dead 2: It deserves to be mentioned here with how Rockstar through sheer brute force content creation managed to make a game where people can really immerse themself into the world in a way that is physical impossible to produce or run in the nineties. A game that bridges the game between story driver and free form larping with a world that truly feels alive.
Cyberpunk 2077: First time I played I did not like it, but on second play after patch 1.6 I really enjoyed it. The constant first person adds immersion, combined with 4k HDR and Dolby Atmos it really draws you into the world. Strong story and good setting&city. Fun gameplay loop and world building. Now that it has been "fixed" I think it is a really good game with good builds and expanded game mechanics like cyberware. But I will wait a couple of weeks more to play it until the mods catch up.
Systemic games & survival:
Frostpunk: Good game that marry city building with survival mechanics, can't remember playing anything similar during the 90s.
Zelda BotW: A game that truly innovates with game mechanics brining immsims into the future. The way the different physic systems interact with each other in a big open world is unique and genre breaking. Combines with open world traversal of climbing and horse riding, survival with correct cloths
Outward: My favorite game. It combines action rpgs with survival. Good build system with mandatory multi class with a strong meaningful perk system. Good easy to use craft system that uses the same interface for crafting, cooking and alchemy. Big open worlds with diverse faunas like in Outcast. Beautiful vistas and strange faunas like Morrowind, big beautiful score. Survival systems that in an immersive way ties into the gameplay, like for example that dungeons are actually pitch black if you have no light source and it's hard to play if you can't see shit. One of the best magic implementations where you need to sacrifice health and stamina to gain a mana bar. A lot of magic is also ritual requiring casting a magic circle with use of a reagent, which you need your alchemy lab to produce from ingredients found in the wild. Local or online coop.
Misc:
Whole slew of good adventure games: Lacuna, Rainswept, Kathy Rain, Deponia, Gemini Rue, Primordia etc etc.
Fora Horizon 5: The Dolby Atmos mixing in the game might be the best made to this date. The storms, planes, tunnels really are moved to the height channels enveloping you. Excellent HDR as well.
Dirt Rally 2.0: Good rally game, best visual and sound to date. The sense of speed is unparalleled.
EA Sports WRC: Upcoming game from Codemasters releasing at the end of the month and is very promising with good graphic and audio combined with a lot of content.
Carrier Command 2: Pure joy as a coop game.
Indie scene with all old genres. Special mention to Vagrus - Riven Realms.
Closing arguments & TLDR;
I strongly believe that the last 10 years evolution of survival games will, with it's inherently systemic design focus, drive an evolution in games. If anything is going to revive immsims it's going to come from the survival games being incorporated as hybrids. Just as we have seen all fps open world shooters become "action rpgs" we will see "survival rpgs". Now I don't my self play survival and crafting games but have friends who do, and they are immensely popular even if not AAA level yet. Games like 7 days to die, SCUM, Green Hell, Valheim and No man's sky. Especially as old rehashes like Diablo 4, Fac Cry 6 and Starfield keeps failing.
We already see the potential in Outward which will eventually be seen as a game before it's time. Combining survival elements like perishable food and mandatory light sources into an rpg and more importantly immediate feedback on the screen not seen sense Ultima Underworld. Zelda BotW has already implement basic survival into its open world but with a strong physic systemic engine and is immensely popular. Red Dead 2 also by basically making a hunting game mainstream.
And on other fronts we also see an evolution to more advanced games which is inherently incline. Escape from Tarkov is poplar precisely because of it's advanced gun systems implemented into the game. Even Squad and Hell Let Loose developers just recently are moving away from casual arcade shooting striving to implement more advanced systems requiring patience. WARNO is a shining example of an rts adding even more complex system instead of dumbing down. Mordhau was also a game incorporating more systems, not fewer.
So sure we are not in the Golden Age, but things are looking bright, I remain hopeful.