It's essentially "social PGP". Instead of your account being owned by your ActivityPub instance, it's owned by your private key, which you use to sign or encrypt events.

Not only you own your account (mathematically), you also own your social graph, since every "follow" is a public cryptographically signed event.

I'm not trying to shill you, just mentioning it to you because I think you may find it interesting. I'm writing to you from nostr, using one of the 2 AP-nostr bridges. Although bridges are hacky, they still allow open platforms to be glued together, and for me to have found your content.