I think bank will still go on but i think they will adopt to crypto may be also day will make their own coins 
Most likely, banks will simply give up the fiat and start using the cryptocurrency as a means of payment over time It is too much to say that the bank will give up and immediately use the crypto currency as the only means of payment. Fiat has long been used and proven to be able to control finances throughout the world and will be difficult to replace it with any other things. For sure bank will improve their technology but it won't ruin the master plan. Crypto can be used as an alternative ways for payment but it won't replace fiat completely.