The issue is that some people want to blog for a living (and there's nothing wrong with that IMO) which leads the platforms to optimize for that. I don't think enough people are willing to spin up their own self-hosted blogs just to throw their thoughts into the aether. Not when points to what the internet has become exists and they can get the engagement/dopamine they want elsewhere.

That's not to say your prediction is wrong, just feels extremely unlikely, barring some massive regulatory upheaval changing the internet's current paradigm.