Right. It would take some act of compulsion to make them comply, or some clever hack to automate scraping and mirroring. While most of the customers accept FB's legitimacy, they still rule, and the effort to hack or legislate might not obviously pay dividends.
Will this last forever, or go the way of MySpace?
FB appears to be more robust than MySpace because of the inertial qualities of its comprehensive membership, but that may be changing.
2020 is the year "surveillance capitalism" entered the popular lexicon, and 2021 has kicked off with an ugliness that could well be transformative. If there is a revolution, new tools, infrastructure, and rules are required to establish new social media platform that avoids the pitfalls of the old.
I cannot imagine FB agreeing to such translators voluntarily.