As far as shrinkflation goes, marketing has tried to maintain profits for company while making us feel better. Well, maybe that was the original plan. (remember the movie Mr. Mom and the tuna fish pricing?) No one wants to see the price of anything go up. I'm not sure when it started, but I feel safe to assume it was during inflationary times. So, for people on a budget, pretty much the majority of middleclass, they feel better about the struggle when prices remain the same. That is a short lived happiness, as it is discovered the product doesn't go as far. So then, portion sizes to family changes (not that is entirely a bad thing) to reflect the smaller product and to maintain budget. Short term, consumers remained brand loyal. Store brands have been around quite some time, although it seems they have gained popularity over the years, as they stretch the budget, and not always as a taste compromise.
It is evident that shrinkflation has run rampant for multiple reasons. Bottom line, while we know about it, people are still buying based on product cost, and not per ounce price. This keeps people on budget. I struggle to not give my advice to people who "look" like they are struggling with money when I'm out shopping. I've never gotten reamed when I did, but do recognize it can make people uncomfortable. On another thread, there was talk about online shopping, and there it's even more important to look at price per (whatever) to get the best deal. Not everyone is savvy enough to do this, as simple as it can be. I believe that people still look at bottom line price to stay on budget, rather than price per (whatever).
We could go round and round on pricing, do manufacturers need to always make record or near record profits? The days of American manufacturers etc. doing what's best for American people has been waning for quite some time now. Who can blame them when everyone is doing it, under pressure from shareholders etc. There are exceptions, and those are the ones we need to support if we can.