I don't think the economies allow for it. The German Sparkasse started as a savings bank and at its core was/is a 'dumb bank' in your words. But at some point c

I don't think the economies allow for it. The German Sparkasse started as a savings bank and at its core was/is a 'dumb bank' in your words. But at some point customers demand financing etc. and would like to get all their basic needs from one bank instead of having multiple. So these banks adapted.