A impossible one in now a days. For instant the people from most developing country start to earn and buy a Bike with instalment. The pure base of bike buying is faced on the credit from the bank. The people use to replace bitcoin to usd by using the bank.Bank became a part of life for now. Many online transaction below 10$, will get the huge free. Like that bank is essential one for now.
What is certain is that life without a bank is like something that is very unlikely because even, when someone is still not tied to a bank, in reality they will find it difficult to carry out wider transactions. Crypto and other assets only as a store of value which means that the real use is still impossible to realize, so the bank becomes something important even though we don't heed it but we will still use it for many purposes.