I think with the development of the world, paper money will be gradually eliminated.
With the development of science and technology, people can freely use their own encryption money, shops, supermarkets, food markets, encryption will be used in all corners.
I think paper money will not disappear. Because not all nations are in favor of crypto and of course, there are still downside to cryptos which real cash/money has. and if paper money disappear what will happen to all the banks? All banks are depending on it. So actually paper money will not disappear in the future.