I think most people are assuming we’ll have the ability to fend off anything. All it’s going to take is Zuck creating a new fediverse-enabled platform and just giving everyone with an Instagram account access using their already existing accounts. We’ll be outnumbered by the millions.
You’re looking at this from the wrong point of view. The fediverse is not just lemmy: Threads, Tumblr, even BlueSky (albeit with their own protocol, but anyone could just modify their fediverse enabled app to convert their data to be applicable to BlueSky’s protocol) are quickly setting the stage for a new norm. The more websites integrate the fediverse into their stack, the more data outside the immediate sphere of influence of these major corporations can be harvested. To what ends they’ll use it, I don’t know – but I don’t trust them with it.