Definitely. Fiat currency is still alive. The earnings we have through bitcoin trading and investing is based on fiat value. And I am sure that you exhanged your bitcoin for fiat currency to buy things you needed. Computers, electricity, internet service, and gadgets that you use to earn bitcoin can be paid still by fiat currency.
yes that is a fact that most of the people are converting their bitcoins in to fiat for buying or doing shopping, actually the main reason behind this is that in most of the area there are no facilities of using bitcoin directly in local shops, but still there are too many opportunities of using bitcoin for online shopping.
Of course, people should still believe in fiat because there are some places or countries that shopping with bitcoin is not easy to come by, hence the only alternative is to convert the bitcoin to fiat for any purchases. So you see, in this situation if there is no fiat one will not find it easy to make any transaction.