So you hold both bitcoin and fiat. What do you spend then?
You have to live somehow, pay your bills, buy food...
I prefer to spend fiat because fiat is inflationary. It loses value over time so holding it doesn't make a lot of sense. I hold only as much fiat money as I'd need for maybe a year if I got sick or had some problems like an accident or a medical condition. Cash is like a hot potato these days with 10% inflation.
Don't worry. I've allocated some money to pay bills, buy food and other necessities, so it doesn't bother me to stick to bitcoin and fiat at the same time. Even though I sometimes sell bitcoins due to a sudden need, I can still hold most of my bitcoins and fiat and buy bitcoins at low prices.
I also prefer to use fiat to shop for daily necessities because there are no offline stores that accept payments using crypto. So until now, I'm still fine
People must hold fiat, no one can avoid fiat because we use fiat for anything we need daily. While holding BTC is mostly intended for investment, so people won't sell it any time, they only sell Bitcoin once it can earn good profits. Ideally, all people do the same as you, holding both fiat and Bitcoin. But we use fiat and Bitcoin for different purposes. We use fiat for daily spending, while Bitcoin for investment.
If they only hold fiat without having any investment, I think they will find it difficult to grow their fiat for future use. With today's progress, it is highly recommended to have an investment in any form, of course, a valid one. And we now have cryptocurrencies, especially bitcoins, that we can invest in long-term. And if we can increase the number of our bitcoins over time, we can earn big profits in the future.