@kissane all of which is to say:
1) We should be encouraging people to get their own domain early in the onboarding process.
2) Fediverse software should support bringing your own domain. Takahē does it; others should follow suit.
3) Fediverse software should support both Webfinger accounts (user@domain.example) and DNS hostname accounts (user.domain.example). That way, everyone gets a domain name, free, right away, but somewhat less under their own control.
@kissane I know that domains have their weaknesses as a root of identity on the Web and the social web.
They've also proved remarkably resilient over the last 30+ years of civilian Internet.
There are some other identity systems, like DIDs, that can supplement DNS, but right now, owning a domain is the best way to control your internet identity.