We'll still have physical cash, it might be as useful as sovereigns and other 'collectible' coins the royal mint produces though. But then when was the last time you saw a £50 note?
It sucks to have no banking service but since I barely have coin to spend anyway I adapted well. What I feel after accomodating lifestyle changes is liberation both in being out of the financial and the societal consumption values systems. I wish I could never use banking again, only pure dirty cash bills but it's nigh impossible to truly eschew the convenience and access of an international online purchase mediated by family and a credit card.