Plenty of products aren't lowering in price, but are getting you more quality for the same price, e.g. a faster CPU or more RAM in your smart phone. Economists consider that a price drop for the calculation of inflation.

That's technically correct, though of course does not feel like it for many people. To the average consumer, a "phone that can play today's games" is the same measurement today as it is next year, and if prices don't change, they might not consider that "quality increase".