Not only that but you also raise the requirements for grocery / department store shopping. In principle all you need to shop at most stores is cash and being able to get to the physical location of the store. With Amazon Go you need a smartphone with a data plan, an amazon account, and a bank account. Even in America not everyone has all of those, or even any one of those. I personally spent a few years as an adult without a bank account. These requirements amount to a "you must be this rich to use this store" sign, and there are easily tens of millions of Americans who are not rich enough to use these stores even if they do have the money to buy some of the goods inside.