Okay I read too much are really believing that it is bitcoin that will be the main money.
Think again. I think we are better than that.
Bitcoin relies with the internet. Paper money dont. It is still the easy way to transact specially with retail stores and with buying food in vendors outside of our houses or in the streets.
Look, what will happen if suddenly internet collapse? Then you will go back to paper money? Or you will do the old time trading with clothes for food or some gold for food? It will get harder to trade again without it.
The paper money or the conventional fiat also relies more on the internet now. Most of the transactions are don online.
No doubt transactions are done online but there are many people who prefer to go for shopping physically and by paying physical money and for them its not easy to switch to bitcoins directly.