Paper money is normal a good pay method but everything is indeed getting more digital and due to that we can say that it will disappear in about 20 years from now without any doubts.
perhaps 20 years to come. digitial money will be more and more and become rampant. but I do not think that paper money will actually disappear. I think there is a transaction that can not be done online or using digital money
I dont know if hat become global, but banks are already allowing several services to be made from home at the phone, like pay bills, scanning the code bars, transfer and follow the account funds anytime, soo i wont be surprised that banks reduce their employers and became digital in the next years, but for those happens internet must be free.