It isn't just Mastercard and Visa, Paypal, Stripe and others (including banks) did the same in a coordinated way even if they are supposed to be rivals. And isn't affecting just Steam and Itch.io, but also porn sites, crowdfunding sites and generative AI training websites.
And happened more or less at the same time the UK mandated personal verification with camera to use NSFW websites and the USA released that new law about theorically revenge porn and non-consentual AI deepfakes.
So yes, these payment management companies are part of the issue, but seems that it comes from above them. There's not a lot of people who could mandate Visa, Mastercard, Paypal and others to do so and maybe also force UK and USA goverment to do laws like that.
And isn't a random retarded feminist group like Collective Shout that nobody knew about them before this.