Ngl that's (in my opinion) one of the biggest obstacles in nearly every idea in the 'non mainstream' space.
In the mainstream, everyone uses Stripe to take people's cards and put money into creator's bank accounts.
Patreon, kofi, itch, buymeacoffee, vgen, you name it, I'll call it a stripe wrapper. (YouTube and twitch may have their own systems iirc)
Accepting fiat means dealing with the regulatory demons, it means compliance questions and people who are very quick to ban anything too 'risky'
Tbh, you piss off one snarky lady in the 'risk management' office who wields too much power and lives every moment, and she takes your entire revenue stream away (rip my boy josh, may the merch run live again....)
So there's this whole writhing pile of snakes under this rock.
Japan and that one Dlsite did interesting things in trying to set up its own payment system, but it's very local only.
EU has quite a few peer to peer advantages through swift it seems (I hear people can just scan QR codes and pay bills and send money?)
Brazil, not to mention everything not okay with Brazil, has PIX. I drove through literal Appalachian level back 'country' and had a group making brooms out of straw holding signs with PIX QR codes wanting to sell me shit.
US is beholden to the ball gag and whip of Visa and Mastercard.
