The Facebook bit is my concern as well.

However, I’m not so sure we’d be able to avoid it, even if big tech did not get involved.

For example, beehaw.org does not federate with a lot of other instances. How long until a few big lemmy instances decide they are important enough to block every new instance by default? Probably not going to happen anytime soon, but it could be a foreshadowing.

I think people should be incentivised to join the smaller instances. But I guess most new people coming to the fediverse don’t know that you can talk with other instances.