I think bitcoin will not replace the bank because Bitcoin is the first non-centralized digital currency,Like money in general, Bitcoin can be used to store wealth and to purchase goods electronically,While banks regulate the circulation of money such as the euro and the dollar..
Their some advantage present in bitcoin which make Bitcoin better than bank 
. Bitcoin is one kind of digital money and its related money transaction occurs in digital and their is no need to give full information of sender and receiver in order use bitcoin transaction facility, But incase of bank you have to give your all personal data. Bitcoin changes low transaction cost and fast processing to its users where as banks are doing opposite of this. In any country their central bank regulates their currency production and distribution but in case of Bitcoin that thing doesn't happen and due this their is instability in its price. 