Future of crypto is deflationary?

So I came across this article that explains inflation and in one moment author says:

Could you imagine what would happen to the economy if you knew that your dollar would be worth more tomorrow than it is today? Spending on goods other than necessities would come to a very dramatic reduction (Note: You might be rethinking crypto right now huh?).

If we want to replace FIAT, there needs to be incentive to spend. But now most of popular projects have deflationary currencies. Is there solution to this on Ethereum?