Any transaction is based on the principle of profit. Bitcoin can't be compared to the Bank because it is so different and the transaction is different.
Yes, I agree with you. Bitcoin can solve the bank's problem especially for the speed of the transaction although bitcoin transaction is not too fast. Still, it is fast bitcoin than the banks. Besides that, bitcoin can be sent to any places without any border, and the fee transaction can reduce no matter how much we want to send the amount.
Those are the key points and biggest advantages of bitcoin. But we cant forget the down side- there are many illegal transactions happening,and there is no way to stop them. besides that there are more pro's than cons