Once the Incomes are being earned in Cryptocurrencies this would mean that even the retail expenses will also be done in Cryptocurrencies and only then we can imagine a life without banks otherwise as of now there is certainly no way this is happening because purchasing Cryptocurrencies itself involved buying it from transfers of Bank.
You can't just get rid of banks like that. Just imagine if there were no bank in this world, you couldn't send money thorough the world or even got income from cryptocurrency because it's involved with Bank. Just face the fact guys, that we can't live without banks.