It depends on which currency can be used for transactions in the country. As more and more countries become familiar with Bitcoin, Bitcoin may be more important in the future.
But if we consider current stage, fiat is more important than bitcoin. People are still knowing bitcoin and day by day the users of bitcoin is increasing. But at this stage, people are using fiat on most of the purposes.
Even if Bitcoin become more familiar with all the countries, fiat's position will always be one notch higher because as you said, people still use fiat for different purposes in life while bitcoin only plays an important role as an investment, even many people don't consider bitcoin to be too important when they don't know and are not interested in investing in bitcoin. The world may lack bitcoin, but it is certainly indispensable to fiat, it is a product of government economics, its role is associated with development and people.