If you're referring to companies direct, then you're wrong cause there are lots of exchanges these days and all of them functions with banks. No cryptocurrency exchange can function without having a bank account, if there is one, the mention it! None. And if you mean in terms of crypto companies providing bank services to individuals, then you're also wrong cause there are lots of wallets that serves for the same purpose as of banks. You can send money through crypto wallet and you can also receive. Then there are some offers debits cards as well, the only difference is that crypto users are meant to stay anonymous.