Even Cambodia has instant bank transfers already figured out. I can basically walk around with just my keys and phone and pay for anything I need from groceries to taxis to bar tabs to school fees. Even the local market sellers use it.
In large parts of the US, it used to be illegal for banks to have branches.
As you can guess, keeping your banks confined to one office in one city is a recipe for them being vulnerable to the fortunes of a single small area.
In contrast, their neighbour to the north, Canada, had a much more stable banking system, that was run by large national chains (just like in most other parts of the developed world).
If you want to learn more, George Selgin has written a lot on the topic. Other keywords to look for are 'unit banking' vs 'branch banking'.
The migration to ISO 20022 is in full swing, finally. We will get there.
The US also has recently seems to have a hesitance toward introducing new regulations that actually seems to have made it harder to change things like these in cases where the private sector isn't able to take the initiative on its own.
I know some time has passed since and a lot of money and effort has been spent in improving things but I'm still pretty impressed just how quick it all works. My banking app notifies me when money is sent or received from my account and it usually beats the checkout confirmation page load time or POS approved message when I make a purchase.
Plus, I think the Buy American Act had the IT waver removed, no?