Earlier quoted context omitted.
Some brands do offer a better product than generics. Just like there’s different quality of silicon chips that result in different quality electronics, I can imagine the same exists for food. Whether or not the price different is worth it is obviously up to the buyer. https://en.wikipedia.org/wiki/Product_binning
I'm desperately trying to find the source but discounters like Lidl/Aldi just use well known brands, signed with NDAs on both sides. Imagine knowing that a discount chain is about to make a regular purchase of 300,000 tins of beans. You will happily rebrand, keep it hushed up and take the repeat large orders. It makes me wonder what the margins are on a single tin of Heinz beans.
I remember there was a whole thing a few years ago about fake olive oil and fake grated Parmesan cheese (or what was mostly wood pulp which was allowable per legal definition). I think Kirkland was one of the real olive oil products, but the point is there were differences and some of the expensive brands were real and some were fake.