>cards don't work perfectly as age verification either.

there are 0 "perfect" age verification systems.

plenty of minors can have their brother/sister/parents supply their id, or do the verification video. the on-device verification discord rolled out was, within hours, broken. i remember news reports of kids submitting photos of their dogs and being verified as of-age.

credit card solves most of the problem with much less downside than submitting my face (i am already okay putting my card info into most sites)