And thats why payment processors should be a public utility

Payment processing being a public utility would result in less access to payment processing for services with a combination of high chargeback/fraud rates and opposition from some sections of the public

We already have blockchain, which is already at-your-own-risk.

you could still have your public provider and a private provider with added services

That's still stupid - surely the solution is to moderate better, not to literally kill the company.

The payment processors don't care about the health of the company, they care about their own survival. If a report is publicly released that there's a significant amount of CSAM material being sold on OnlyFans and they are knowingly facilitating it, the potential costs to them both in legal troubles and PR is substantially greater than the revenue they get from OnlyFans. Worst case scenario is OnlyFans goes bust and some new company comes along with a similar business model but better moderation.