Its a bad analogy.

If an online liquor store was systematically ignoring ABC laws and shipping booze to underage customers across state lines, MC would probably act in a similar way.

No, I'm not contradicting myself, I'm saying the level of authority should be appropriate to the issue at hand. Child abuse apparently widespread enough to go beyond Pornhub's already existing moderation implies some responsibility for the payment processors, and also at the end of the day responsibility of the law enforcement. What I'm saying is there is no division of labour in the sense of outsourcing everything to law enforcement, or everything to Pornhub.