To this comment and others. I don't actually even mean that the existential threat is people choosing to leave. I mean that the progression of banned accounts will spread like an actual pandemic because of the rule that any account that associates with a banned account will also become banned.

I mean to say that everything will seem fine and suddenly they will find that their algo has banned most of their users, like a play-store zombie apocalypse. It will seem instant and inexplicable to them, and the damage will be done.