The biggest change have to be us, the players. Almost every game let it be an indie or a triple-A blockbuster have been researched and min-maxed by most players. Not just the "sweats" but the casuals too. Of course official guides and playthrough books have been a thing back in the 90s too, almost every PS1 game had one. But now with the internet, reddit, Discord etc. people can come together and basically "solve" the game they play. I see this everywhere. It's not even about the game being hand-holdy or not it's the fact that players can datamine and simulate every aspect of the game. Elden Ring is a perfect example recently where builds are min maxed to edge as possible. And that's a mainly single player title, there is not even anything on the line. MMOs are kinda dying because of this mentality, especially WoW everyone expected to have the best build doing the best possible dps or else. Even in very casual games like Animal Crossing you have this mentality of having the best villagers in the game, people asking insane amount of money to visit their islands ot get that best item you need etc. So yeah, I'd say this is the biggest change.