I find that very believable. My completely unsubstantiated conspiracy theory is that OnlyFans is a money-laundering and dragnet-style-blackmail campaign for unlawful mass surveillance. I can’t imagine a normal or even abnormal person paying content makers, but I could imagine contractors and NGOs smurfing payments.
I have a friend who pays (or at least paid) for cam shows. I don't understand it either because there's so much free content, but then you have cases like the guy who murdered his parents because he'd sent hundreds of thousands of dollars to a cam performer who he thought he was in love with.[0]
0. https://en.wikipedia.org/wiki/Grant_Amato