Oh sure, banks will still have things to do after they're no longer issuing debit cards and processing checks and getting in the way of electronic transactions.
Banks will still make loans and give away toasters and try to sign you up for various financial products you don't need. But they won't be controlling transactions.
Right now, things like Apple Pay (and its imitators) are sitting clumsily in the middle of a cumbersome old-school transaction infrastructure, with banks and credit-card companies acting as the gatekeepers. But that's temporary.