I think that online multiplayer games does not need to exist as most games could be played offline with AI and with higher enjoyment also.
I think the reason a lot of people don’t enjoy AI offline instead of multiplayer games is because as a capitalist society we associate multiplayer games with higher joy, due to the huge amount of ads and streamers targeting teenagers to show them how much fun they are missing by not playing in online multiplayer games. I had met a variety of people with different ages and a lot of the older generations prefer offline games and consider it the norm.
At least for me, who was a disabled kid who literally couldn’t go out and play under the sun, online multi-players were my salvation. For collaborative games, such as MMOs, few things are as fun as a full squad with comms, whole party of friends investigating a brand new dungeon. Or the gorgeous chaos of a full chain of command, creating strategies and forming friendships in the heat of a 60 v 60 battle, gathering resources beforehand to make yourself useful, the commaradery of giving your old, engraved armor and weapons to your guild’s treasury, or to a growing player you took under your wing.
A lot of its allure is for isolated people, a place to build a community and sure, chatting is a significant aspect, but once you know your squadmates, everything flows just better.