If it's something made by the government or by banks then you should definitly know that it won't be private and they will have control of everything just like the banks right , nothing much will change .
and for what comes to the Paper money I don't think it will dissapaear , maybe on some countries yes but worldwide ?definitly not because some countries don't even use Credit cards for their transactions so ... yep
Yes i also think that paper money will stay and will not disappear. Because even if the bitcoin will be an international crypto-currrency, the government always want control on a specific money. Because through this they can earn or corruption may exist. People mostly the powerful one always crave on control and manipulation and bitcoin is not a type of currency that can be manipulated by someone. Even of the developers do not have the power to control it. So in conclusion, as bitcoin develops for the better transaction and security paper money will also develop for future needs.
That´s why goverments and banks will issue their own cryptocoins or rather a digital version of actual fiat coins. They will control the emission, they will watch all the movements and they will even know who is the owner of every address. Furthermore, they will avoid counterfeit.