Think of BTC as gold. How does gold create value? Because people are willing to trade fiat currency for gold, at a rate of exchange that is constantly changing.

There is a limit to how much gold there is on earth. Getting the "next ounce" of gold becomes increasingly more difficult over time. There is a limited amount of BTC, getting the next BTC becomes increasingly more difficult over time.

Although (some believe) that gold is a decent store of value over longer periods of time, gold is not recognized as a useful currently to use to buy everyday items at the grocery store. You have to convert into fiat to buy your groceries.

And now for the most controversial part of my answer - I believe BTC is as useful for everyday transactions as gold is today. Not very. And will never be the appropriate currency to use for every day transactions.

There are and will be many ways of transacting that are going to be permanently far superior to either gold or BTC.

Gold and BTC probably always have an important niche to play in total financial system. But not as a daily method of exchange or transactions.