> Why are there expensive rewards programs? Because consumers like them! And they insist on paying with a credit card because of them.

That is very US-centric - for example, this all does not hold in Germany (many people are actually still cautious of credit cards there).

> Payment costs won't materially decrease unless someone invents a form of payment that consumers prefer which doesn't have these cost burdens.

In the EU, there is: SEPA direct debit.