I can see that the future of paper money seems to fall too but it doesn't mean it will make the economy of a country fall too. It will only make a difference on what we use to see, government bodies will certainly make the same thing as crypto currency or should I say a digital money and it's going to happen in the future.
Yes, if you will read what I've said that there would be change with the paper money but there would be no mean of making the economy to fall. And it's what I've saying that paper money will be replaced by another means of payment and has monetary value. And that's a real speculation, we are near to become a cashless society.
Of course people choose the most simplest like using a card for pay everything, but i'm sure some developed country still use paper money. I mean the future of the paper money is still exist in some countries, but on modern country like USA, Japan and Korea, they can easily move on into cashless society.