Paper money is disappearing, thankfully, we do have the technology and capability to create more secure and paperless transactions, also crime would go down in an alarming rate, another type of criminals would rise too but anyways the entire world could be a safer place
It is really very much difficult to predict the future of paper money at the very present time. It is because of the fact that still people do believe in paper money and other than this, none of the crypto currency has been declared as legal currency so far. Till that time, there will remain the existence of paper money in this world but after that, things will be changed very much significantly.