Inflation is not price increases. If that is the definition then the metric is effectively useless. Prices can increase for any number of reasons, looking only at price changes doesn't tell us anything meaningful or actionable.
It absolutely does when the correct definition is still used. Inflation is an increase in money supply, that's really all there is to it.
Your point is why the use of "inflation" to mean price increases is so meaningless. Prices change for any number of reasons and you need context. When "inflation" still means in increase in the money supply there is no context required to know what it means, though obviously that's not all the information you need to understand the economy.
You are wrong and that's why you are misunderstood. I would suggest just saying "increase in money supply" if you mean increase of money supply instead of using a term that means "a continuing rise in the general price level". That will make people understand what you mean.
[0] https://www.clevelandfed.org/center-for-inflation-research/i...
[1] https://www.dol.gov/general/topic/statistics/inflation
[2] https://www.ecb.europa.eu/ecb-and-you/explainers/tell-me-mor...
That doesn't change the fact that the attempt to redefine it both co-opted the word and made it functionally useless. Prices change for all kinds of reasons. The amount of change alone is meaningless and using that meaning of the word allows economists today to play a lot of shell games with the numbers.
This is totally false. It dates to the inter-War period, specifically, to describe Weimar hyperinflation. (If you just look at money supply, it was bad. If you look at prices it was the disaster that it was.)
That's exactly how words get redefined.