Mastercard’s ties to the esports world have led to more evidence of censorship. A source leaked messages from the Riot Games sponsor to livestream channels during the Valorant Champions Tour. The payment processor asked moderators to delete messages accusing it of forcing the ban of Steam games.
Stripe is a payment processor. It has different payment methods it supports. Which are MasterCard and Visa. But it does also support(if you can use it and the merchant accepts it): Giro card, other card options, Revolut Pay and other options. Those avoid the MasterCard, Visa ecosystem.
Regardless, not everyone wants to use or uses Stripe. And it’s a bad thing for everyone to use Stripe just because of their interoperability because that then gives stripe too much power.
Plus, for a company like Valve, the fees of Stripe would severely affect their revenue.