You do not need a bank before you can use bitcoin or other crypto.
He asked for a "crypto businesses"!
There is no business that is larger than one man store that can run on only bitcoin, you need to pay bills, you need to pay wages, you need to pay suppliers and there is no way any company would survive on crypto-made deals!
But I am always wondering why people are depending on banks on what they can have without bank.
So you're telling me that you haven't used a bank in the last two years, or a service derived from a bank not even once!
Might work for a while in some complete black market economies in 3rd world countries but it's not going to happen if you want to run a business in either US or EU.
With Silvergate and Signature gone, Millenium cutting ties with crypto and Simple sold, the few that are crypto-friendly and deeply interconnected with exchanges that are left are probably Ally Bank, USAA, and..cough, cough.. BoA. Not on the same level of friendliness as the others but at least they have Coinbase integration and they do state, they have no problem with you actively trading and buying crypto through their account.