My impression is that this results in *some* shaping of policies between instances, and some breaking of connections. Every time a new notable instance comes along (Threads, Bluesky, etc) there's a debate, lines are drawn, and people sort themselves into one side or the other.
A byproduct of all this is there is a lot of anger when the admins of larger instances make a decision that puts them on one side or the other of that line.