A similar disruptive bank started in the Netherlands this week. Its a real bank accessible by app only: https://www.bunq.com/
The plans are big so we have to see.
I can see things like blockchains improving back office settlements and clearing, sure, but... whatever?
Disrupting the actual financial system is nothing short of disrupting how society who gets what, and what gets done. This is not a technological problem you're dealing with.