There is outright deception going on.
I happened to notice one day awhile back that the Peanut butter we buy had less peanut butter in it (marked on the package with less ounces in it in small type) yet the jar was the exact same size and both were filled to approximately the same level in the jar.
Then I turned it over and realized what they had done.
This picture in shows sorta what I am talking about though the type we buy has a much more pronounced indention in the bottom.
I noticed too that the tuna had less in it (marked very small on the package again) yet the can was the exact same size. then just filled the can with less tuna and put in more water or oil.
I have a pic of my mom's kitchen from back in the 90s that shows a "One Pound" bag of Doritos on the counter next to her Microwave. I noticed that you don't see "One Pound" bags much anymore the usually have 11.5 ozs. or there abouts. I took one of the new bags and placed it next to her microwave and took a pic from about the same position and you can tell the bag is almost exactly the same size. Canned goods and such all seem to have less in them now yet the prices continue to climb.
My wife found Trisket crackers on Sale and bought a bunch. We opened one up and it was barely 1/3 full. Why do you need that big of a box with 2/3 of it containing nothing but air? Because it makes it look like the consumer is getting much more than he really is.