The point being made is really just the identity of user being tied to User@domain.tld vs @handle it seems like that concept has died with Web 2.0. Only thing I would improve of the fediverse. If communities could be merged with when a group of instances agree to form a network. Like how IRC does it with channels. I mean yeah there would be netsplits from time to time but it would cut down on duplication and increase the traffic of niche communities like the benefits of central platforms get but it’s still distributed.
No one was just thinking about it from high school back in the 90s