I think the idea of crypto is that we will not need banks anymore. If crypto gets bigger, more scalable and more widely accepted it can be used for payment and you won't need a bank. What would you want to use a bank for?
I think bank is still necessary in development of economy. Bank offer a loan that help businesses develop. Its true there is a crypto that offer a loan and i do think in the future loan will be offered by institution that adopt blockchain and it will be our new bank.