US banks are weird [1]. Archaic. Slow. Filthy rich. Incompetent. And yet they're nearly impossible to disrupt due to the benefit of size. Starting a new bank is expensive, unless you want to pretend at being a real bank and letting another bank handling all of the nitty-gritty details. In which case you've now become a reseller of that bank, and will likely be even worse.

The only thing that can disrupt US banks is consumer outrage, of which there seems to be very little.

[1] Source: I've consulted for some of the largest US, European and African banks.