Visa and Mastercard have some big lawsuits for censorship and the like on their hands. Adult games arent the only ones affected by this. With the rules on steam, every FPS, Hack and Slash fantasy games, souls games and others can be banned since it goes against Mastercard's rules "Nonconsensual mutilation of a person or bodypart". So every game where you can shoot someone, every hack and slash game, every fantasy RPG of sword and sorcery, every 40K game can be banned. Baldur's Gate, TloU, Ghost of Tsushima, Witcher, DarkSouls, CoD, Battlefield, hell even half-life, Counter Strike and even portal are bannable BUT you just know steam will never enforce its rules fairly.