Banks will never disappear. After all, they provice some services that are really needed by the people or entrepreneurs. I'm actually OK with that, as long as you have the chance to opt-out peacefully of this system and change to a better alternative.
Just give it a few more years and some more robustness on layer 2 solutations a some sidechains taking a big chunk of transactions from the mainchain.
If banks did not had the power of fractional reserve banking I will be fine with their existence and their business model but since they can print as much money as they like and then make you pay interests on those loans then their business model is dishonest and this needs to change, bitcoin offers a solution to that problem since they cannot print bitcoin at will like what they can do with fiat but I am sure they are planning already a way around this if bitcoin becomes as popular as we think it will.