There's something interesting about to happen. On July 6th, Otherside, the Bored Ape Yacht Club's metaverse, will have a load test. Everybody who bought NFTs for land in their metaverse gets to try to log in. The whole system is supposed to go live in mid-July.
Yuga Labs outsourced their metaverse to Animoca Brands and Improbable. Improbable has been working on scaling technology for very large multiplayer games for years.
There have been working games (Worlds Adrift, Scavengers) using their technology. It does seem to work,
although game devs say it's a pain to use.
But it's very expensive to run, because it requires a lot of servers and large amounts of communication between them to coordinate a big world with tens of thousands of players in one space. Originally it had to be run on Google's "cloud", and the game operator paid for every event that went to the servers. Three indy free to play games, and one rather nice-looking world (Nostos) from China, went live, got users, and went broke. Lesson: free to play not compatible with the server cost of this approach.
Otherside/BAYC is all people with lots of spending money. They all paid at least US$3000 to get in. Some paid much more. None of that "inclusive" stuff. So they've paid for the operating cost.
It's extroverted people; BAYC runs raves for them. It's people into FOMO. That's a very attractive customer pool to advertisers.