I feel you, but Mastodon has about 9 million users and BlueSky has 15 million (if the first results from a search index are to be trusted), but I could not find anywhere even close to 60% of the people in this hobby on Mastodon as I have on BlueSky.

There was a very concentrated push recently of artists (I think it was artists originally) to go to BlueSky and it’s sort of echoed into similarish hobbies. So that’s probably why the user makeup is a little different.