If this were something like bitcoin, the payment could be wallet to wallet. If it were credit, some processor would have to know that they process transaction for "$Me" and find transaction #N to settle it back with the POS.
So the question really comes down to how you would implement this "payment bus". It seems like it could theoretically be something like the stock market. In fact, credit companies could be market makers and offering to settle transactions for consumers at different rates. This would have to be fast enough to be usable, but it seems like that issue is solvable with HFT solutions. But how would you get existing companies who make their own custom and profitable buses to all agree to use one generic bus and move the money making to the credit side?
A credit card is just a token that represents an intermediary that both sides trust to handle the payment. Apple Pay simply abstracts that and improves the user experience, while reducing the leakage of informaition to incidental observers.
Replaced by what, the likes of PayPal? No thanks.
Just because the US banking system and Wall Street behaves like some spoiled child that shits in the kitchen and is given an award for doing so, doesn't mean the solution is an even less regulated company that operates like a bank, but isn't bound by the same rules.
Oh, nice. May I ask who bears the costs and takes the credit risk? When you pay through an intermediary such as a bank, a card issuer or PayPal, all sorts of costs and risks creep in, due to infrastructure costs, chargebacks, fraud, etc. Who takes care of the bill?
I'm separately arguing for a competitive credit market, freed from the banks.
People are confusing the issue of multiple "virtualised credit cards" leading to more competition in the consumer credit product markets. It seems like a backwards way of thinking.