Mastodon

Facebook launched in 2004, 19 years ago, and bears more responsibility than just about any organization in Silicon Valley for the proliferation of abusive, invasive, proprietary, walled garden social media platforms. They function as an integral pillar of the state's mass surveillance and propaganda operations. They have been complicit in many pogroms, including a genocide in Myanmar.

I assure you, they haven't suddenly had a change of heart. They have a long history of acquiring their competitors and rolling them into their own private corporate infrastructure. If they intend to make a move on the Fediverse, there is no reason to believe their intent is any different than what their corporate history demonstrates.