It is true that Lemmy sucks for having substantial reach. If I wanted to reach the largest possible audience for advocacy's sake, I would use corpo socials. They optimize for the largest reach because that's where they make money, so it's hard for a non profit effort to compete.

However, that's not why I use Lemmy. I don't use it for building a mass movement, but for building community free of corporate interference. A place where we don't have fascists debating the existence of trans people. This isn't a town square, but a collection of punk clubs that kick Nazis out without needing to appeal to some landlord.

Also, in case you haven't noticed, the Overton Window is being legally pushed to the right by the largest English speaking government in the world. There is no freedom of speech or dissent, and corporate media will fully cooperate with the government in their efforts to ban any left wing organizing. There is no marketplace of ideas to debate in on those platforms, as even when there wasn't open fascism like now, the right were always given more leeway to be radical. Pre musk Twitter protected fascist accounts like Libs of Tik Tok while those accounts now run both the government and the companies.

At least here we can always rebuild if instances get censored. At least here we can be more than censored opposition.