You're both correct. Individual SKUs varying by $1-2 between two different metros isn't surprising or unrealistic. Stores also adjust pricing weekly, and items on offer tend to rotate as well, so comparing point-in-time prices could be volatile. None of this means the inflation didn't occur, just that one specific example may not be telling the full picture.

In my area, the Malt-O-Meal knockoff version ("Tootie Fruities") is $5.99/30oz ($0.20/oz).

I point this out because it always seems weird to me that discussing housing / utilities / healthcare / education costs somehow get boiled down to grocery store pricing disparities, when grocery stores allow you to comparison shop (and real estate / electricity / oil / etc don't).

Because this method of judging inflation by using “equivalent” substitutes completely ignores the change in quality of life.

Real inflation is what happens when my behavior doesn’t change at all, but my costs increase.

If I keep making adjustments to my behaviors then I’m just trying to counteract inflation, it doesn’t mean inflation isn’t happening.

That's actually a very fair point, thank you!