No company operates in a vacuum. Particularly, companies in commodity based industries, like grocery chains, which average maybe 3-5% gross margins, cannot arbitrarily increase prices without consequences (drop in demand). People will shift their purchasing power elsewhere. Unless, of course, every where else is also increasing prices because of the sheer amount of excess monetary liquidity sloshing around in the economy.
> People will shift their purchasing power elsewhere.
You are neglecting that people may not have a choice.
For people w/o cars, they are limited to whatever grocery stores are within walking distance, or accessible by mass transit.
In my case, my easiest choices are the extremely overpriced organic store, Safeway, or QFC. Once Safeway and QFC merge, I'll be down to basically two local choices, and I live in a major metro.
I know people who have one grocery store around them. There are parts of the country[1] where in a ~15+ mile radius you have a single choice for shopping.
Now throw in people who don't have the time, or ability, to commute, and many grocery stores can charge whatever the heck they want up to the limit of what consumers can afford.
From that thread, yes indeed, the price increase is 76% for 2019 to 2022, but that is (obviously) a completely absurd level of price increases for a 3 year timespan.
And this isn't some unique situation, this is pricing at one of America's largest grocery retailers, a grocery store chain that is the sole grocery store in many communities, and a grocery store chain that is set to soon become much larger.
[1] This isn't unusual, in Washington State if you go outside any major city, you find that smaller cities/towns basically have one Safeway for the surrounding area and that is it. Visiting friends on the east coast, I noticed a similar situation, a cluster of small towns and a single grocery store (Kroger owned).