There are already some huge maps out there, Just Cause 2 and 3 both have maps at around 1000km2, and those games are beloved by their players. But if the next Cyberpunk game was announced with Night City now being the size of an actual large metropolis, say like New York, would you say that’s too big? What determines what “too big” is?
They don’t work. Vanguard did it way back when, with their three continent world. Each one had enough content to get from lvl 1 to lvl 50, the max, and your starting race determined your starting location. It could take up to an hour to get to friends. Even on the same continent, with a mount (before they added flying mounts), it could take a half hour of running to cross the map… and players complained so vociferously that they were forced to add fast travel options.
I don’t think that means it didn’t work, I think that just means it’s not for everyone. I’m a firm believer that, “given the opportunity, players will optimize the fun out of a game”. Small indie games take firm stances on their gameplay all the time, not every game is for everyone, and that’s ok, that’s how you get unique and interesting gameplay experiences. But that’s easy for and indie game to do because making an indie game is cheap.
MMOs have the unfortunate reality that they’re architecturally complex, and expensive to operate, and thus need to appeal to as wide of an audience as possible to justify their existence to investors. They don’t have the luxury of making the experience they want, which is why they all end up just copying WoW’s enshittified gameplay, but with less polish.
My hope is that this indie revolution we’re in expands to “large scale” multiplayer games. Not so massive that it’s prohibitively expensive to run, but not so small that it’s a ghost town. I think that’s when we’ll start to see interesting MMO experiences again.