On the Facebook thing...
They're not trying to join the Fedi. They're trying to bring us into the FB/Insta sphere. You can argue that because it's AP-based that's not the case but I think you'd be wrong. The power imbalance is at least three orders of magnitude.
I'm in the Fediverse because I need social media and community that's essentially free from fascists and their pals, and from corporate manipulation of algorithms to shove them onto my feed whether I want them there or not. Ideally I want this freedom at the wider network level which I effectively have now because of great instances like this that have robust de-fed policies.
If I want to be on Facebook I'll reactivate my sleeping account. If I want to be on Instagram I'll use the account I probably have there but haven't used since the 14th century.
Frankly I think anyone who thinks they're acting in good faith is so gullible they should check their own shoelaces right now because I promise I just tied them together