it is just a service that is offered on money. these services are so many different things. such as loans, credit cards, savings account, Checking accounts, other types of account i don't know the name of in English , Insurance stuff, Mortgages, Safty Deposit boxes, ...
banks doesn't have to be affected by bitcoin or bockchain technology. it is just a different form of money!
Yes, banks has their ways of milking the public such as loans, mortgages, unnecessary bank charges and so on.
Bitcoin will not entirely remove banks out of the way because Governments and majority of the people are still using bank for their financial saving.