Any transaction with a business or stranger there will still be a market for something reversible, disputable, and with insurance against scams. They also hook into currently exchanges automatically for you when paying overseas and their jurisdiction for pulling back your money is global rather than just in your country.
FedNow is a Zelle/ACH killer, they don't provide direct-to-consumer services and if your bank or consortium of banks ever issues cards/apps that can be used at new POS systems they will have just invented Visa, and there's no reason Visa won't support settlement with Fednow over ACH. You could already cut out Visa with a "Pay with Zelle" type scheme but there's little appetite for it even in countries where their version of FedNow has existed for years.