i still believe in fiat, because in my offline life, there is no store that receive bitcoin as payment. because bitcoin still not accepting by every country and there are a few country that already accepting bitcoin as their payment. and if bitcoin is available on every store in my country, then maybe i use fiat as my investment 
First point is that bitcoin is being used by every country their citizens just need an internet connection to take start with it, and it is true that bitcoin is not accepted by offline shops but you can easily use it online for shopping those things which you need for your offline life, and if bitcoin started to be accepted in offline life then I think the fiat will be converted by everyone to bitcoin in order to make it secure and to use t there.