There is a small possibility right now because not everybody in the business is into bitcoin. It means you have to trade your monthly income just to convert it into fiat. How could we deal with the market fluctuations. This is impossible right now but maybe in the future.
We may not be far away from a time when it becomes possible to simply use bitcoin for the majority of your transactions. If you live in a place where crypto debit cards work freely, then you really only need fiat for physical cash on hand for very minor transactions if at all.