Seems like payment processing would do well to be a public good instead of a for-profit venture to me.

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?

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.