Part of it is "the curse of good enough": the US has had good credit-card style infrastructure for over a century and digital infrastructure since the POTS days. Part of it is that we lost our appetite for anti-trust in the 80s. Part of it is that the price structure of this infrastructure has wormed its way into everything in a way that is difficult to undo without causing high-visibility inconvenience for low-visibility benefit. The good-enough is the enemy of the good.
Germany is another first mover with decades old banking systems and standards. German banks also dragged their feet supporting SEPA Instant or they added additional fees so that barely anybody wanted to use it.
Then the EU stepped in with regulation: If you support classic SEPA transactions, you also have to support SEPA Instant for the same price (which is almost always free for retail banking accounts). And suddenly banks did.
I think the “recent” change allowing merchants to pass along the credit card fees is a step in the right direction.
I think a lot of people would still choose fraud protection for the extra costs, though.
Not to take away from your example, but I was under the impression that transaction fees charged when using a credit card in the US were significantly more than in say, the EU?