FedNow will not become an alternative to consumer payment cards anytime soon, if ever. Visa & Mastercard work very well for payments between strangers.
But who says that the same party has to offer payment rails and dispute protection? There are successful models of the two being decoupled in some markets (e.g. various providers offering fraud/chargeback insurance on top of SEPA Direct Debit in Europe).
I'd never buy an airline ticket in cash, for example: If the airline were to go bankrupt (which has affected me more than once in my lifetime), I'd have no recourse.