Every level of my government has been defrauded of a significant amount of money (relative to their budget,) in the last five years; I do not support their losing more of my money to fraud.
Certainly, once you have a world government. Are you sure that a world government will be aligned with your interests in other areas than payment processing?
I'm certain that the payment processors aren't aligned with my interests!
FedNOW is open for public use and supported by a number of major banks, so it’s not clear what the additional thing you’re proposing here is.