Here's 3 interrelated things that happened, I guess:

1. Corporatization.
2. Centralization.
3. Moving away from privacy by default.

Essentially, a few companies have found a good way to make money on the Internet: gather your personal information, and use it to put advertisements in front of your eyeballs. Part of that is figuring out every little preference, trigger, and micro-identity you have so you can be fed increasingly targeted ads, and be cajoled into engaging more and more with these advertising platforms.

Are you a liberal recently single White gay man who owns a condo in a gentrified urban neighborhood in a major US city in the Pasific Northwest, who is between 25-35 and who cares deeply about social justice? Here's some suggested products specifically tailored to you, along with some communities you can join that our algorithm has found keeps people with similar characteristics on the platform for longer periods of time. Is that increased engagement due to the discovery of a warm and welcoming community or an unending flow of rage bait? Doesn't matter! If you become increasingly attached to your community, we'll sell you things that appeal to you along those lines. If you become increasingly despondent and enraged, will sell you a solution for that too.