@jeremiahlee.com (@Jeremiah@alpaca.gold) you’re right that the #IndieWeb is more of a movement. It’s a community based on shared values & principles¹, one of which is plurality², explicitly prioritizing interoperability over any “particular piece of technology”.
As to “subdomains as usernames using #ActivityPub?”, myself and others are using our (sub)domains as usernames, e.g. via the #BridgyFed service³. Mine should be self-evident in the header of this post wherever you’re reading #fediverse posts.
Completely agree that “a link that also works as a mention name is obvious / intuitable”, have been practicing that for a while, and wrote up some notes about how & why:
which I should organize into a longer blog post at some point.