Not possible life without bank because many people need to borrow money from the bank and make their business, not available for borrowing in bitcoin and altcoin and then not have institution available for every one could borrow bitcoin or altcoin, now day many country have several bank kinds and give good service for every one to save their money.
Yes its not possible for now because banks has a participation to our economy to boom. Its like a cycle giving and taking. So crypto and banks will co exist and that would be beneficial for us right? There's no need to get rid the banks because its essential part of our lives and economy.
Banks aren't that important for those persons which are only dealing in cryptocurrencies but if someone wants cash then they somehow always need a bank in the process. Also for the people who doesn't know about bitcoins and what cryptocurrencies are, they always need banks and are an essential part of their lives. There should be a way devised to remove the necessity of banks for selling and buying cryptocurrencies in general. If a project is developed to solve this problem then I bet the ICO will raise tremendous amount of funds.
Well, those who invested or dealing in cryptocurrency only will need banks soon. When BTC hits ATH, they will convert it now into fiat and where do you think they will put that huge money? definitely in banks. Banks always serve as a great part, especially in our economy. It has a lot of advantages and makes it very important that must exist in a community.