There are lots of Fediverse alternatives to social media, including Lemmy (which I guess you know about?) and the ones people have mentioned here already (Mastodon, Pixelfed, Loops, PeerTube). The advantage of the Fediverse is that it can’t be co-opted by a single bad actor, in the way that Musk took over Twitter and made it into a Nazi bar.
Yes, exactly. There are some things on this list where, if everyone opposed to fascism did one of them, we’d win tomorrow. Realistically, not everyone will, but it’s still the right thing to do, to prise every bit of power from their grasp.