I think the main point is not about the "paper" or not, but the currency itself. Assume all nation worldwide has paper money of their currencies. They (every country) can make "non-paper" or digitalized money IF THEY WANT. Ex; Japan can make their JPY in digital version, US also can make their USD in non-paper money if they want to. The matter is as long as the value of that currency is as expected in control, no matter the physics. Once more every country can make their currency in non-paper, means paper money extinct (IF THEY WANT)

The question then is why they still considering paper money? The answer can be started from question too : are the grass-root citizens ready to use digital currency? When the rich one also "techie" can make a purchase by just tapping their smartphone on the payment system device, then how the poor-slum-dog can buy something? What to be tapped?

Then I think the answer of your question about the future of money is it can be still exist, or can be extinct.