While I find this fascinating, what these monopolies do with their power, I wonder more what the alternatives are... There where some interesting Economist articles on major changes to financial techs aiming to break this though that was years ago and I don't remember much other then discussion of micro loans and government cryptos schemes

Why would payment processors lie?

This is basically what I said earlier was probably their driving factor.

Mastercard has not evaluated any game or required restrictions of any activity on game creator sites and platforms, contrary to media reports and allegations.

Our payment network follows standards based on the rule of law. Put simply, we allow all lawful purchases on our network. At the same time, we require merchants to have appropriate controls to ensure Mastercard cards cannot be used for unlawful purchases, including illegal adult content.

Payment processors do not care about someone's social norms. Payment processors, however, do not want to get in trouble with a country, because getting their ability to operate in a country suspended would be really bad for them. As a result, countries have lots of leverage over payment processors, which is a good way to apply pressure to commercial websites that use payment processor services.

Collective Shout is in Australia. There are laws against some forms of adult content in Australia.

https://en.wikipedia.org/wiki/List_of_banned_video_games_in_Australia

With the R18+ rating in place, it is expected fewer video games will be given the Refused Classification rating. Games may still be Refused Classification if deemed to contain material unsuitable for R18+ classification, such as depictions of sexual violence or the promotion of illegal drug use, as well as drug use that is related to incentives and rewards. More specifically, games which may be Refused Classification include:

• Detailed instruction or promotion in matters of crime or violence.
• Depiction of rape.
• The promotion or provision of instruction in paedophile activity.
• Descriptions or depictions of child sexual abuse or any other exploitative or offensive descriptions or depictions involving a person who is, or appears to be, a child under 18 years.
• Gratuitous, exploitative or offensive depictions of: (i) violence with a very high degree of impact or which are excessively frequent, prolonged or detailed; (ii) cruelty or real violence which are very detailed or which have an extremely high impact; (iii) sexual violence
• Depictions of practices such as bestiality
• Gratuitous, exploitative or offensive depictions of: (i) activity accompanied by fetishes or practices that are offensive or abhorrent; (ii) incest fantasies or other fantasies that are offensive or abhorrent

Classification is compulsory, and games refused classification by the ACB are banned for sale, hire or public exhibition, carrying a maximum fine of $275,000 and/or 10 years in jail.

There is some material available on some of these online stores --- at least globally, and I'd guess in Australia --- that violates those restrictions. Payment processors won't risk getting in trouble with countries.

But I'm not in Australia!

Probably not, but it's also not just Australia that has similar morality laws.

What I'd guess that the online stores are going to most likely do is have lawyers sit down, review the various countries that they sell games in, write up some list summarizing legal restrictions and embed that into their selling policy and add that it's not legal advice, the list may not be current and complete, and that if some published game does wind up violating the law in some country, that they may remove it from sale in that country to conform to the law. Then they're going to re-list the stuff that they're comfortable saying is conformant in the countries where it is conformant. At least some of them have already intended that (a) there's some kind of review process going on and (b) that they expect to be doing reinstatement of games.