My evening thought:
ActivityPub/Mastodon works best for groups of people that share some common interest. People with a "we" attitude. Where we talk eye to eye, not from top to bottom.
Centralised social networks however have made many of us believe that all social networks focus on people with a "me first" attitude. The more egoistic people that base their value on metrics like followers and reach.
That's a fundamental dilemma that pops up every time people move from "there" to "here".