I think the market for that is growing, but they'd have to thread a very tight needle reputation wise. The credit card business relies heavily on trust, and the major networks like Visa have literally decades of reputation behind them.
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.
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.