I don't think that paper money will be used in the future anymore, since producing paper money is impacting our environment greatly, paper money can be faked (technically) while cryptocurrency is almost impossible to be faked on. Cryptocurrency is also a safer alternative to paper money. I think we will see this starting to be introduce in around 10-20 years because the community who doesn't understand the beauty of cryptocurrency will refuse it to be implemented.
In the future, there maybe a cryptocurrency that is going to replace our traditional stock.
Agreed, now the direction to eliminate paper money is increasingly clear, for example many countries are trying to reduce cash transactions and replace them with digital money.
Digital technology will be the trend for the future, it's fast and easy, however, the problem here is that the world does not have the cash, it will be better for the rich, with the poor will be a disadvantage. Because the rich have bank accounts, they will be guaranteed better privacy and benefits but the poor have no account, even they do not know anything about banking services, they will not have the benefit, so I believe the paper money will still exist for a long time until this problem is resolved, and it is not easy to solve.