I haven't done any hacking on activitypub so I don't know too much about that but is it because of the simplicity with the nostr protocol that makes it easier than activitypub?
Discussion
yeah it's simpler, I don't have to run my own node, easier to migrate my contacts. Can't be banned by power mad admins (the fediverse is infested with these kinds of people). I had to migrate to a new node a couple times and it was torture.
I have a work in progress activitypub node[1] but the protocol is such a pain in the ass I gave up