One is the higher incidence of chargebacks. You don't have to ask if something is naughty -- just look for the chargebacks and it'll tell you. What happens is someone charges a thing, their partner sees it on the CC statement and asks about it, the first person is ashamed to admit it so they act shocked and insist it MUST be fraud because THEY would never charge something like that, and to keep up appearances, they call the bank and have the charge reversed. And platforms have to build in large margins to cover for it, or screw creators out of their payouts, or sometimes both and keep the difference.

(Which is why something irreversible, like cryptocurrency, keeps getting talked about. It wouldn't solve the shame problem, but it would eliminate chargebacks, and creators would just get paid. It just brings a bunch of other problems.)

The second is extremely vocal pressure from some fringe religious groups, who will pump the bellows of the CSAM-PR-disaster furnace for anyone who allows a nipple on their platform. You don't know the groups' names, but you've seen the hit pieces they put in the press. Look up "Exodus Cry" for one.