Exactly, I don't believe that payment processors want to play the role of gatekeepers (after all, they lose revenue for every customer they turn down). They probably just want to show that they can self-regulate to give Congress less of a reason to pass something like this[1].

I think people underestimate how much moral regulation in the US actually comes top-down under the guise of anti-trafficking law (remember SESTA/FOSTA and how it killed Craigslist personals?)

[1] https://www.congress.gov/bill/117th-congress/house-bill/808/...