Think Privacy.com/Lithic.com but using crypto and instant fiat->crypto conversions when the payments are made. No chargebacks, no refunds. The crypto or stablecoin are decentralized rails.
You'd have to build your own infrastructure, but you could make an actual credit card. It would have to be super jank at first (you might even have to cut actual physical checks at first). Fundamentally, a credit card is just you paying for somebody's transactions, and billing them at the end of the month (and suing them if they don't pay up).
It would be slow, and the service would be horrible, but the people accepting your money don't have a ton of other options.
And fundamentally the reason that credit cards have that customer trust is that they make it easy for customers to get refunds when the product isn't delivered, which is very hard to do for an Onlyfans-like business where there's no way to "return faulty goods" - standing in the middle between clients who think they didn't get what they paid for and sellers who think someone just wants to copy their pics without paying is not going to be a fun place to be.