In addition to what you said, I think additional aspects to consider are the open standards and protocols Facebook/Meta have already abandoned once it became convenient to do so:
XMPP access for Messenger/Chat
RSS feeds for any newsfeed source. They even continued to use the RSS badge (which is unofficial as far as I’m aware) for their follow icon even after they removed RSS feeds.
The bare minimum price of Meta’s integration into the Fediverse should be nothing less than the return of those standards, and honestly even that may not be enough.