I think that the bank is more important that the authorities , because they can rule fiat banking . In fact bitcoin bank should not , but people still need to get to the bank fiat after getting converted from a bitcoin. So now , the bank does not disappear , because bitcoin. In the future.
Bitcoin will make bank disappear in the near future but currently it need to be trusted and popular among majority of the population of the world.
Even if bitcoin gains huge popularity in future its impossible that it can make banks disappear, banks are trusted organizations and its not easy for people to quit banks and switch to bitcoins.