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.
> All U.S. financial institutions (Receiving Depository Financial Institutions or RDFIs) must participate and accept Same Day ACH credit transactions.
> However, sending (originating) Same Day ACH payments is optional for banks and credit unions.
In the USA, no single regulator have that power. Basically only congress can do something like this. The us Congress ain't famous for being fast, you know.
The countries that have innovated the most in regards to automated payments are the ones trying to escape US influence: look at PIX in Brazil, BRICS pay, etc...
In America, the payment system is an oligarchy, they protect their own (the bankers), what need is there for innovation when they are making a killing out of the current inefficiency?
The one place where the US haven't been slow is in stablecoins, making them dollar donominated, to ensure the monopoly the US dollar has on international trade stays strong. That way, when the US has a crisis, they take down the rest of the world too, to the joy of non-US countries.
For other examples, look at adoption of login.gov vs id.me, and tax filing software solutions.
I’ve never been in a position where I needed a cash transfer to an account the very same day, I have tens of thousands of dollars of credit available so there’s very little need for immediate transfers, at least for me personally. I do virtually all of my spending on credit cards so I have up to 60 days to pay the loan back without interest.