I think that if you want BlueSky like growth for activity pub… You federate with Threads. Or another hypothetical flagship where everyone is sent. Stop worrying spreading users around so much. People who join that network on the flagship can learn about federation and instance switching later.
I’m sure many people on activitypub would prefer that it grows more like it has though.
Because you install the app, make an account, and use it and now it has more celebs I guess.