Theres no chance for a digital currency  in placing a   fiat currency. We all know  that  fiat  is  being  used  by all people  all  over the world and  it already  established  its  name and  its uses  worldwide  and  for bitcoin  no matter  how  it flies  , it cant still  place  fiat currency , so this means  banks  would be  still there because  fiat  do store  on banks.