Bitcoin is behaving more like an asset class (gold, property etc). People who want to store wealth away from the prying eyes of govt. People in places like Venezuela and Argentina who are dealing with delinquent currencies and want something to hold it's value.
But in the west normal fiat will continue to be used to purchase the necessities of life.
that's because there is still no real way to earn bitcoin easily for the average people aside from buying which is not convenient for many, and also it feel like investment, many don't want to invest, they want to acquire, you don't invest to have fiat, you acquire it, so until bitcoin will not be easy to acquire it will no be on par with fiat
It'll never be easy to acquire for everyone.
Let's say a boss will pay all of his employees in BTC. The boss is the person that has to get through the hassle of getting that BTC.
Mining is the only way to get Bitcoins these days and that's not accessible for the simple man anymore sadly.