The identity ownership is very key as it is a big issue with centralised and decentralised social networks. Hubzilla comes close with its nomadic identity, but that still has to be moved from server to server (or you host your own Hubzilla server). In this way Nostr’s identity is seamless as you register once with your public/private key, and whatever app or Nostr web service you use, it is synced via the relays, and you can post from anywhere (no imports/exports/restores). Secure Scuttlebutt has peer-to-peer identity, but each peer is a different identity. You can “merge” them, but it causes masses of issues with syncing new posts etc.

The other thing it is solving is there is no dependency on a server login nor a server to publish your posts. Any one, or more, of available relays makes your posts available. It has a clever way of letting followers know what relays you use vs what they use, so they can always follow you. And by the way Nostr actually has a Lemmy type service too, but I see very few were actually using it (or know about it). I think I touched on it in my own video when I looked at Nostr.

To me, it is quite an interesting network as real effort seems to have gone into addressing some common shortcomings. We could see that the Zot protocol was more advanced than ActivityPub, but guess what (like VHS and Betamax) ActivityPub won in popular usage. And of course this year ActivityPub got W3 open standards approval for social networking.

That said, I’m not sure how the ActivityPub protocol may be overhauled to support some of the solutions above. It is a whole different way of managing identity. It becomes this protocol vs that protocol. Yet there is a Nostr-ActivityPub bridge so maybe something is possible.