[runeks]

I disagree. The purpose of a crypto exchange is to exchange crypto for national currency. This requires interaction with national banks because banks are the only entities that can hold national currency in digital form. E.g. to hold USD you need a correspondent bank in the US somewhere.

Bitfinex, which is incorporated in the Cayman Islands, is an example of your “ideal” bank. It has seen its US correspondent banks flee several times, leaving Bitfinex users unable to withdraw USD.

Coinbase is a US regulated exchange which US banks are much more willing to cooperate with since they perceive it as safer than working with some Cayman Island outfit.