Choosing host is more important than it should be. Mainly because hosts are trying to do 2 things at the same time: being identity provider and being some kind of content host in federated environment (moderation etc).
Because of this when you choosing a host, you are investing too much. Their future policy changes etc will effect you, you cannot afaik move to another host. (like moving your email)
When you give people choice, things are much harder. On other platforms we have few choices depending on what you will publish (media type mainly), but here more like topic based separation, which is making things tricky, as we are humans with many different sides.