i think it will never .
why ? because bitcoin say . nobody control your BTC and there is no fee . so if bitcoin had bank it will had fee and somebody will control it .
Banks not only charge fees - they also provide interest. This is one reason why people might be tempted to give their bitcoins to banks.
On control - I agree that we will be losing control if you give your coins to a bank. It is up to you to decide whether the interest offered is sufficient for the loss of control.