

It’s an interesting project, but NodeBB and Discourse have been working on adding activitypub support, so people who prefer bb style forums will probably use those. I don’t think they integrate that well with lemmy yet, but I think it’s being worked on.
A lot of instances block it. You can check the moderated servers section on your instance about page to see if it’s blocked.
Meta does a terrible job moderating, so it can be a massive amount of extra work dealing with shitty people from there. They also have policy agreements to collect your data if you federate with them.