Since I do the cooking in our family, I do the grocery shopping. If that red apple costs too much, I may substitute a cheaper granny smith. The price decrease doesn't reflect the real price of computing power. The cheaper computer I could buy today is much more powerful. It makes calculating a spreadsheet or surfing the Internet easier and faster.
People change where they shop in response to price increases.
If I think the jeans at my favorite department store cost more than I am willing to pay right now, I might wait to buy new ones until I'm in the neighborhood of a jeans outlet store. Jeans are easily patched, after all, and old ones certainly feel better. Some economists agreed with it. Others said there was bias in the CPI, but not as much as the commission believes. The bottom-line problem here is the real world is an incredibly complicated place.