our govt farms the authorization out to banks (multiple of them), seems to work well. There is also a govt auth on top of that if you don't want that.

Banks can't just ban you, nor just take your money. The price they pay for being gatekeepers is a ton of regulation.

This is why PayPal for the longest time made it really clear that "we are not a bank". So that they wouldn't be subject to those regulations and could suspend accounts and keep the money.