That can be important for some home cooks that don't have time or experience to make a "knock off" product. Case in point: Campbell's mushroom soup in green bean casseroles, a Thanksgiving / Christmas staple in some areas. Campbell's has an iconic flavor that off-brand soups don't match.
With some fiddling, I can adjust Fareway's mushroom soup, but if I'm going to the trouble to make that dish for company, I go get the Campbell's and pay the inflated price.
Ditto Lipton onion dip, another iconic treat.
To be far, I've mostly been serving steamed fresh or frozen veggies with a hint of good virgin olive oil. I'd rather save the calories for some pumpkin pie.