Bank for bitcoins are not needed. It require lots of energy. Hope this can happen when BTC is accepted worldwide and we do nave a physical bitcoins as like other local currencies along with in digital format. But as of now, wallets are more than enough and we are well settled with its function and features. Really more adequate and comfortable.
however BANK I think is very important. because with the bitcoin bank certainly we would be guaranteed funding. This as well as an exchange, but more reliable legality. when there is bitcoin bank then this will be better.