I think it's just sameness fatigue.
You have to observe the process for a while to understand the dynamic and when you do, it can appear that everything is just cyclic and boring. So an unbelievable number of people are now "aging out" of the 10-15 year period of exposure you need to understand what's worth engaging with and what isn't.
It's a certain realization that the original utopia of an interconnected places where everyone can share and everyone is interested in a broad number of topics and everyone can be nice for the purpose of discussion, is ending. Maybe I don't care for the big platform that has everything and everyone, because most of everything and most of everyone is not actually interesting to me. Regardless of whether they're bots or not.
If it's entertaining, it being fake isn't a problem. But if it's fake AND boring... why stick around.
tldr: the internet hasn't changed, we have. Or it did, but that's not the point.