I'm a big fan of people trying to make new social networks, but personally I'm not interested in any new system not built on open protocols. Otherwise incentives are such that it's just going to turn into Facebook eventually.
I'm also very interested in open protocols, like Matrix and DeSo. However I disagree that everything has to turn into a media behemoth like Facebook. You make what you measure.
And one way or another you're going to end up measuring money eventually. Unless you are exceptionally altruistic, the only way to avoid selling out is to align incentives from the beginning. In practice this means forcing yourself to compete directly with alternative implementations, by building on open protocols. I'm not going to trust my time to your altruism.