Instead of asking
why these problems are endemic to every platform, people just say "let's try silver bullet #24 so that we can keep doing the same pernicious stuff with a veneer of progress" and now you have several
more problems on top of the ones that already existed.
Are humans in large numbers capable of interfacing with individual human beings without engaging in pernicious behavior? The answer, as anyone online in the last twenty-five years is a resounding no. Are humans in large numbers capable of behaving immaculately when it comes to preserving their own or their customer's privacy? Once again the answer, as anyone online in the last twenty-five years (and several decades longer if you include proto-business networks) is a resounding no. If you add progressively more humans to anything, does the output improve? If the metric is human satisfaction, the answer is no. If the metric is the rate of return in a Ponzi scheme, then yes, okay, you've got me there. The cause of almost all problems is solutions.
As far as social media goes, it's literally designed to use people to promulgate human-motivated pseudo-information for as long as humanly possible. It's not for "socializing" or "meeting people" in the same way that TV shows and movies aren't there for entertainment. It's to sell the viewer's attention to people that have anything but their interest in mind. Moving to federated enclaves is just further deregulating an already throughly pernicious industry.