Idea and concept are good but it could be good and promising only on paper, but like mentioned bitcoin is not physical. This is problem and this cannot be done for the moment. Maybe in one country as pilot program and to see how will it be. Maybe some bank will try to test it but think that eventually they will steal all those coins in the end.
Crypto banks are simply a mediator, therefore there is no special need for them. For calculations in cryptocurrency, wallet and its function is completely enough, and money can be exchanged on the exchange. Besides, the operations can be carried out by using smart contracts: for example, delayed payment, warranties are possible there. Crypto banks are something "extra" for now.