I believe you, because the store is always out of the most popular products, and nobody ever seems to figure out that they could simply shift production towards the more popular products and make more money?
On a local basis I can go to two of the same store a few miles apart and one will out of products X, Y, and Z, but the other store may be out of X, T, and R. Localized buying trends can have significant differences.
Also, there may be many other effects here. For example, if a popular product is actually popular and the pipeline to make the product is months long, well there's going to be outages. Shifting production generally isn't easy and trends pass quickly.
In addition, perceived popularity can be used to manipulate consumer pricing. "X is always out. Oh look X is in stock now, I should buy it for 50% more"
I think some suppliers just aren't that good at adapting supply to demand.
prior to covid? last few years have not been representative about how well the supply chain works over the past 50 years.