I think one of the main reasons why I like ps1 games is because they were still trying to understand how to do a 3D game. So every developer would come up with their own vision of what a 3D game should be. No other games to be inspired by, just sheer, original trials, unique visions of a game.
Nowadays every game has the same pattern, every brand knows what is a safe bet for a game, what the mainstream would like, etc. But the devs from ps1/N64 had no such thing. They had to come up with their own ideas. That's also the reason why a lot of people don't know where to go, how to attack, where to explore, etc, in a ps1 game. Is something new that you need to understand, not just your average safe-path game from nowadays.