Meta is probably the only large tech company where we would be better off if they had never existed. Or, at the very least, it nothing of value would be lost.
FB Marketplace, but that's about it. Even that is a hot bed for people like bike thieves.
Since information is rather scarce, here's my shameless plug for a related blog post I made, which includes a few links at the end to more resources https://denvaar.dev/posts/jacobsons_rank.html
EDIT: It's Asthma - https://youtu.be/h0hkoee6sI8?si=NaR4GZjUppQE78xm