Economies today are incredibly complex, because products and services are complex, laws are complex, and trade is international.
There is a need for people who specialize in risk assessment for loans and investment to separate the wheat from the chaff for new business ideas. It would be very hard I think to recreate some alternative institution that does not by in large recreate the same structure and incentives of modern banking.
Cryptocurrency advocates have multiple times had to learn the same hard lessons as fiat currency users.
The gatekeepers mostly get to police themselves. If you’re on the inside you can practically get away with financial murder.
The incentives are too perverse. Who wouldn’t skim or manipulate a few million dollars to make their life more comfortable? Only the kind of people who wouldn’t pursue banking in the first place.