im sure it can...but it will take a long time to make bank dissapear...
but make sure that all people know what is btc...in my country just a less people know bitcoin...
I dont think so that bank will be disappear because it is strongly build. I can say that bitcion will defeat bank but it can never disappear it. Bank will stay even bitcoin is much popular. There are still people who will choose bank that bitcoin especially for those who didn't understand what bitcoin is.
Millenials might find btc more interesting but still there were more still people who depends in bank for their savings.