It’s a good question.

It’s a shift in thinking. In the fiat system you borrow money now to spend and become in debt. You do this because the cost of good increases over time, so you must spend now.

In bitcoin, you save first and accumulate the capital needed to purchase the good or service first. When my savings increase in value enough, you buy the newer car you need or whatever. You do this because goods and services become cheaper over time.

Now why would a spend it. Well you still need to eat, have housing, pay bills, go on vacation and all the things you want to spend money on. You just save it first and are prudent because you have to decide if the opportunity cost is worth the product or service.

Over time the the big wings will lessen and it will become more stable but as long as demand for bitcoin is greater than fixed supply price will go up in terms of dollars. Dollar supply is always expanding while bitcoin supply is on a fixed distribution.