It's not that hard to find a different minecraft server, there are bazillions of server lists. That would be the equivalent of changing guild or being in several guilds at the same time.
I don't think we humans want to be part of a large crowd. More like part of one or more small groups. Before the internet it was mostly one. Now you can easily do several.
This really depends on the MMO. In World of Warcraft, yes this is majorly the case in the past few years. In games like FFXIV, this is most certainly not the case.
WoW enables the behavior of only playing with your guild because the community at large is toxic which is also enabled by the game.
FFXIV has a much stronger community, players greeting each other in cities, sitting down to watch a Bard play video game music on a harp or everyone chatting in party chat through cutscenes in main story dungeons.
There is a sense of community in these games that draws people to them. I think certain groups of people do want to be a part of a large crowd, but not when doing so puts them at risk of being put down like in WoW.
I get the sense something more integrated at the user experience level is being suggested here as ‘metaverse’. I guess part of my read on that is cynical - if true it suggests a winner takes operator all at the centre with some kind of app/content ecosystem alongside. Perhaps I’m reading the roblox comparisons too literally.