enshitification isn't limited to ads being included or increased in a given thing.
it's about the company producing the product or service, treating the desire of their investors above those of their customers to the detriment of the long term survival of the company and/or degradation of existing features and functionality of the products or services in question.
the idea here is by taking the product or service out of one company's hands, they can't deliver what their investors want while degrading their product or service, because people will walk over to a competitor.
it sounds good in theory, but the idea that you could decentralize such things in the same way as email ignores the fact that spam exists because of this and most email services now block email unless it comes from approved forwarders and domains which basically means if you do your email from some place not 'approved' it might be treated as second class or not delivered at all. it's also one thing to decentralize something like email, but a serial media type of service has to store data. what share of your communication is going some server that is used for evil or is turned off at some point? how would that system even be organized?
maybe this guy thinks social media could be implemented like IRC and servers follow the same protocol but aren't interconnected.
i find it really hard to care either way if social media turns to crap. a website forum / feedback post is as close as i get to social media. let it die in fire and rip everyone off involved. it seems more harmful than any good in provides to users.