Suikoden. Dozens of characters to recruit, some with pretty obscure or difficult prerequisites. Hidden sidequests. S2 has a hidden timed sidequestline that is counting down from the moment you beat the game and you're unlikely to know what to do and finish it in time without a walkthrough. Also minigames like gambling with dice, old fashioned card games, cooking contests, horse racing time trials, etc.
I played Suikoden 2 a few years back for approximately 8-10 hours after recommendations like yours and I'm not sure it qualifies.
-Towns are non-interactive. Outside of the standard shops, Talking to NPCs doesn't net any gameplay relevance (side quests, items given, clues as to where hidden item x is, hints regarding deeper gameplay mechanics). All they do is talk about everyday BORING LIFE stuff. I can only conclude the game devs are very lame.
Everything in the environment is static except these boring NPCs, no hidden items or secrets.
-Progressing the story doesn't require any investigation or smarts. You just watch the cutscene. Meanwhile in FF you have to do things like Find dagger after she runs off and ask around for where she might be, figure out how to escape corel prison which requires jumping through some hoops and besting the desert, help locke break out celes when the town is under martial law in an adventure game-like moment, trying to get past the guards and looking for secret passages and so on. Usually simple, but fun nonetheless and it's
something.
-First dungeon was nothing special, but acceptable. Second dungeon was literally just a linear bland cave with no fantasy element, shit music, zero puzzle or element of interactivity, uninspired aesthetics, that left a bad taste in my mouth. Just the blandest cave imaginable.
-Character building (RPG systems) non-existent outside of equipping a couple stat buff gem thingies per character.
-There was one sub-game (a turn-based military strategy game), boring, but most notably it did not loop back to the main gameplay. In Final Fantasy, all the stupid mini-games at least tie into the core gameplay by rewarding you with special items/cash/whatever depending on performance in the mini game.
-there's an open world, so I went off exploring. Nothing was of any relevance. A gate to the north was closed, not even an item given as a pittance. It's a big field too, so I went on a random battle adventure for quite a while but was rewarded with fuck all but boring combat. In FF, world map exploration has hidden random encounters, occasional side locations of relevance, opportunities to learn enemy skills etc.
Also storyfag thing AND an assumption but...100 characters or whatever = that's too damn broad storyfag ambition, resulting in not much story substance/character building for any given character. World building\the world itself was just boring too. Maybe the game gets better later but it stretched my patience and standards thin.
TL;DR 90s FF is the prestigious king of JRPG and the competition isn't anywhere near close.