This is completely anecdotal but at least in my friends circle in the US a lot of people have stopped using Facebook (Messenger is different) or they use it for very specific purposes like Marketplace, specific events, or major life updates. None of those are really engagement driving activities. It seems like most of Facebook's growth is coming from developing nations and older generations who are just now finding about it or haven't bothered moving on to other forms of social media.

Anecdotally, I've known several folks who've left Facebook for one reason or another, often at least in part because of the poor experience they had on the platform.

> Or at least it drives up engagement up until a person-specific breaking point.

Surely as this plays out, Facebook will see it's userbase fall out at some point...

My guess is that they've determined what that breaking point is and have optimized for it.