I'm all for privacy, security, federation, etc. I love mastodon, use matrix every day, hell I self host nextcloud - but if you think that any of these platforms will EVER be as big as their counterparts (matrix -> discord, masto -> twitter, etc) then you're just delusional. Again, hate big tech, tracking companies, etc, but by having so much data they have the power to propel themselves to the top and stay there, if you're a service that respects privacy and don't collect data, you're fucked.