I think one of the best things about the fediverse is that it allows for a diverse set of paradigms.
A “twitter-like” experience isn’t for everyone and it’s great to have variety. I have friends who mostly use bookwyrm—a fediverse “goodreads” alternative—and it’s awesome that I can still follow and interact with them even though I picked a different fediverse option.
@PriorProject @PorkrollPosadist
All the examples you provided were infrastructure, not social communities, so I think it’s a poor comparison.
Instead, I’d compare AP federation to _social_ constructs. Communities, clubs, groups of friends. Even larger constructs like cities or nation states.
In _those_ examples it’s clear that limiting association is commonplace and healthy.