The problem is loaning money - it can be only trough the banks, loan sharks, family/friends and investors. Banks of course guard themselves from loss trough collaterals and laws.
Life without banks would be possible, but growth of businesses and speed of living would be much lower. By saying speed of living would be slower I mean that you would have to earn money first then buy something like car or apartment - you would have to save money for years before buying and now you can lend money from bank and buy it in month or two.
so your only concern is lending or loaning money ? but i see many crypto platforms now also offers a service like this .
living without banks is still possible imo . the reason why banks still here because many people still cant move on or not yet aware that there is already a crypto existing on the online world . they think banks is too useful for them so they say things like they cant live without the help of a bank .