They request ID for bans so that they can ban you personally. ID checks may as well be a sign that you've already been banned and they're fishing for ways to make the ban harder to evade. Venmo does the same thing.
Maybe Anthropic just likes creating a market for dark identities. Because that's the most likely effect of such stupidity; generating more ID theft victims with no change to services to criminals.
> ID checks may as well be a sign that you've already been banned and they're fishing for ways to make the ban harder to evade.
So identity verification is basically a canary that your account is about to get banned, or is on the chopping block. At that point you're better off abandoning ship rather than handing over your ID.