I don't want to generalize too much from my own window into Facebook, but it does look like they may be in a feedback loop. As more and more toxic conservative garbage gets reshared, progressives start ditching Facebook. That means the remaining userbase likes that stuff more, so the feed gets tuned to make it more prominent. That turns off more progressives, who drop out. Rinse, lather, repeat.
When I go on Facebook now, it looks like Internet Fox News, and that's despite trying very hard to unfollow the people who reshare that stuff.
Even the left-leaning content on Facebook has gotten more extreme and virulent. It's just a miserable hellhole now of two tribes screaming at each other while the feed AI fans the flames.