Earlier quoted context omitted.
I heard that the ActivityPub protocol is pretty inefficient when you have lots of small instances, so I would think joining an existing instance should be preferred. I'm not sure why you think that switching instances is too hard for avg people but running your own isn't?
> the ActivityPub protocol is pretty inefficient when you have lots of small instances This seems like a pretty fundamental design flaw. It means that redundancy is there—you can always find another instance if you're made homeless—but self-sovereignty was not prioritized in the design. The kind of person who's attracted to the idea of federation is going to be disproportionately likely to want to self-host, so the s…
Note the 'federation capacity' which is described further down.
If you are federating to many sites (because your users are following many users across different sites), that can get expensive in terms of time/network/cpu.
Even if you are self hosting, it is most efficient if your users tend to follow other users at a limited number of other sites so that the processing threads don't get too congested. Furthermore, if something on your instance goes viral and everyone starts boosting it and following your sites users it can significantly impact the performance.
If you are expecting to be making connections to tens of thousands of instances, the cost of an instance for that network / cpu load is going to be significantly higher than the average person can support / administer / host.
This gets to a bit of a paradox - the more you want to distribute and federate, the more expensive it is to stand up an instance and the more market forces will encourage users to go to the central hosts.