True that.  I was in the working group that made activity pub.  We really pushed hard for them to follow standards on identity that would have made all of this SO much easier.  Got 80% of the way there, I think.  In retrospect, could have been better, but could have been a whole lot worse.  A decent AP / Nostr integration could help, but of course, the way things are now, folks are tribal.  Discovery can actually be quite good on AP as it theoretically inherits from Linked Data.  Not sure on the algorithm front ... isnt it just pluggable?