I mean inflation itself as a formula has been constantly tinkered with to make it look nicer, excluding extreme changes (unless they beneficially contribute to under-representing the actual inflation).
For example, inflation was supposed to be on average 4-5% YoY for the past ~5 years here in the UK, yet somehow everything that matters - food, bills, rent, etc. - went up by 50-70% if not more in that period.