Paper money will stay forever.
Why? Because its easier to make than coins.
Yes paper money would last forever because the first money that we have.it is also our currency that can we used to buy other things.but there is also an important thing about coins its can helps us because it is digital currency that we can used in electronic system.
I do not agree with you because with the passage of time everything change and so will be happens with the paper money. If we look the past there was no paper money. All the trade would be done through barter system.
Then gold took place and then after a long tine paper money was introduced and now the time comes that digital currency will take place and the paper money will be disappear.