Thought about this, good idea, could start with a credit union or something.
the Banking licence is the key.
Let's say your plan is successful and you are able to get a license and start this bank are you ready to not be included in the corresponding banks payment system? No matter how hard you try your bank will have to comply to the very old shit we were here to dissolve and, in the end, you would bow to your masters and become yet another bank.
I don't see it working, sorry.