no, defederation does not “just” do those things
defederation refuses to give them an in to slowly make changes to the platform that will eventually give way to a centralized power dynamic over the whole fediverse
see also: the chrome/chromium monopoly and its effect on the modern web
we love underdogs with poor human rights records and sentence protesters to death for not moving out of their homes <3 the crown prince of saudi arabia is so oppressed
honestly we should have collectively realized way earlier that putting all the useful, readable, un-touched-by-SEO help content for basically every niche hobby fandom and ideology in the hands of one for-profit entity was not very wisdom-pilled of us
what you are saying is true if you entirely ignore the power of a majority market share and the demand that puts on small developers.
even if it’s not universal demand, all you need is a slight majority.
see what happened, for example, with xmpp: https://ploum.net/2023-06-23-how-to-kill-decentralised-networks.html