Banking is the true oldest profession. It might be that the barriers-to-entry and minimum viable customer base are sufficient to keep out most ventures without serious subject matter expertise and deep pockets backing.
>banking is the oldest profession.
I hope you're not serious about that.
That's really more of a comment on market size than anything else, though. Everytime money moves it's an opportunity to profit.
The Big Six made most of that money and they don't do much actual traditional banking these days. The other 6500 US banks are hardly raking it in.