Bank for cryptocurrency will ruin the basic principle of being your own bank without the need to trust any 3rd party. However it might serve good purpose due to some people being used to ordinary banking which means that they are used to ask somebody for every trouble they have. They don't want to think for themselves. But banking with crypto should be secure, very secure. There are some banks trying to be made such as crypterium and bankera but we have yet to see what they can do.
The banking service that I'm pointing is that you can ask them to loan. Yes it will ruin the basic principle of crypto itself but we can't also remove the beauty with the banking service if you are in need.
all you can say is that we may need a much simpler version of the banks that offer some of the services a banks does.
This is what I'm saying, like the loaning service and other forms of investments that they can offer to help their depositors.