You can buy junk food from almost any market, but WF is great because you can assume that everything they have is of reasonable quality, that their meat + fish is reasonably more sustainable / quality-controlled than elsewhere, that their produce is reasonably fresh, etc. It's more about saving time from not having to research every apple farm and figure out their distribution networks when I just want an apple. Also, their return policy is super generous ("I bought this brand and I actually don't like it" = money back), their lines move quickly (sometimes Safeway is a 30min wait), they're rarely sold out of things, and they have some higher-end products which are hard to find elsewhere (I like some fancy cheeses and cured meats). They have some of the same stuff at other places, sometimes for less money, but it's never more convenient or a one-stop-shop.