Paper money must have always been in circulation, it's just that the denominations on the paper are getting bigger and bigger. As technology becomes more and more advanced, the use of smartphones is also common in many small cities. If the world can be connected to the Internet. Then the utilization rate of banknotes will definitely decrease. But it will still exist, and it will not disappear completely. I hope to pay by mobile phone in the future, which is more convenient. But it will be convenient for thieves to steal things, so watch your personal belongings.