AliPay, WeChat Pay, and PayPay succeed because they don’t target this market at all — they target cashed based transactions and provide cash-equivalents. The whole reason why people use them in Asia is because people could use cash but it’s inconvenient to collect and store. These are far and above lower value transactions where fees are important but not as important as simply existing.

I think QR payments can exist in the US if they do the same things that happen in asia: you charge via cash and the balance is stored with the provider. There aren’t any ACH transactions to reverse. If you allow charging with ACH you only cover a small amount and you control risk accordingly.