I don't agree on your statement because fiat money is very popular since from the start of currency exchange of fiat money, and paper money is very useful on local buy and sale like in the public markets how could you say that it would be destroyed and yet people were always patronize it all the time and specially with bitcoin transactions in wallet cash out. This paper money is the gateway to btc so that you can hold in cash form of your bitcoin online balance so paper money is very important as you earn your bitcoin.
I agree, paper money will not disappear because it is very convenient payment method in many situations. Bitcoin will not replace paper money in the future, but it will exist on an equal footing with them.
I agree with your opinion. Bitcoin should be considered as an alternative currency. He has entered into our lives, and took his place. We must learn to use both the dollar and the Bitcoins