Domain names as handles are a cool idea, and you can already do a variant of them in the "fediverse" either by hosting your own instance of a service or by configuring a WebFinger alias (which is what I do).
I'm less convinced by DIDs[1], which is what Bluesky seems to run on: I've yet to see an explanation for why the DID standard exists, given that it effectively punts all semantics (including basic things like cryptographic verification) onto unstandardized "methods" in an uncontrolled global namespace.