The Fediverse also includes the streams repository with a Facebook alternative (made by Friendica's creator at the end of a long string of forks). It offers blocking of accounts/channels as well as entire instances, and on the admin side, it even has a user agent filter that can block servers by user agent/server software. It's capable of locking out e.g. the entirety of Mastodon in one fell swoop, but it's just as capable of locking out Threads, which is what it was originally designed for.