They don’t. They also don’t have a huge disincentive to get rid of it, and people have good engagement numbers with content they hate.
As you said this is a dumb timeline. One where it is a valid hope not that people that run social media companies will decide to avoid toxicity so they don’t contribute to both the death of innocent people but also social order, but that once it happens some lawsuit against them will land in front of a jury that doesn’t give a crap about how technically difficult it is to do, doesn’t care that it might be the new “public square”, and does care that someone died and awards a staggeringly large damages value and an ever larger punitive value. Enough so that the rest of the social media companies worry about bankruptcy.
Of corse that leaves X out in the cold since Leon won’t think it can happen to him, and nobody else has the power at that company to make him…but we can hope that specifically is the company that takes the hit so the other learn the lesson.
Yep, stupid cursed timeline, but not entirely without hope!