They’re probably not doing it just because, my guess is that it’s to appeal to the fasci- I mean- conservative government heading the US right now. And yes, I am aware that they are probably going to restrict more stuff as time goes on if they’re unimpeded. I’m just looking for a solid motive
I see two possible explanations:
Class warfare. The same people banning porn are the ones banning abortion, banning homosexuality, banning gender transitions (although they never seem to ban the same therapies for cis people), banning sex education, banning contraception. All of these attacks on individual sexuality are to try to push people into unprotected heterosexual sex. At the same time, these same political groups have been attacking both parental support systems and child labor laws. They want parents too desperate to rebel. They want children working. They want a larger supply of labor: more supply means more competition amongst workers for wages, which means the labor is cheaper.
Power. Maybe these payments processors don’t actually care about pornographic games. But attacking pornography in the name of “defending women and children” is easy to sell to the public and sets a precedent for these payment processors violating neutrality. So eventually they will move to banning games that are too violent (well, they’ve already been trying for decades). Then it’ll be games that are too “extreme” or promote “terrorism”. If these payment processors don’t see any consequences soon, I expect in the next 5 years they will try to take down any games that are anti-Zionist. Maybe games that are pro-Ukraine. In 10 years it could be any sort of left-leaning game. Disco Elysium for promoting communism. Horizon for depicting climate change. Stardew Valley for allowing same-sex relationships and being anti-corporate.
Notice that these discussions never seem to apply to copaganda. It’s perfectly fine to be violent and bloody as long as that violence is authorized by the state. The US Military offices have a well-documented relationship with Activision for Call of Duty, so you aren’t going to see any of these groups call for CoD to be banned.