This is a technical solution to a non-technical problem.

My risk to my credit number being stolen is honestly low. The risk is the merchant providing a substandard service 99% of the time, and an OAuth style payment flow does nothing for that.

Someone like Amazon who is a trusted merchant already negotiates fees with their banks and they likely already have an extremely low fee rate.

What Stripe, Square and PayPal provide is a service for integrators who don’t want to spend money talking to a bank, negotiating a rate, and then implementing the required security to execute their own transactions.