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 
Of course, the same with my country there are not much stores that are accepting bitcoins, if I cannot use fiat then I could not survive living in our country, bitcoin is just good for online transactions and investment as well but the truth is we need the two, fiat and bitcoins.