In the early years, many hyped up people in the public used "deflation" as a form of argument.
Actually the utility of bitcoin or any other cryptos doesn't actually create a deflation, it follows inflation and "correct" it with new variables in the equations so the economy remain simple but more tech-influenced.

It is also a way to earn extras into a user's pocket as well. It has the ability to create a new economy by itself if adoption increast to about 10% world population. That is what banks and central banks are afraid of.