Comment by vector_spaces

I hope that you recognize that your casual-outsider evaluation of the assortments of these stores is deeply flawed and not based on actual data. If you think about it even just a little bit, you'll recognize that it wouldn't make sense for a supermarket in one of the highest median income cities in the country to have assortment parity with a chain targeting cost conscious shoppers. The devil here is in the long-tail, which is definitionally less visible to you as a shopper, and in fact may not exist at all for certain retailers -- especially those targeting cost-conscious shoppers.