I mean, when I’ve visited San Francisco, it seems to have supermarkets all over the place too (albeit rather expensive, not-very-good ones), so they even have a local model.
When I visited SF I found that to be the case in some neighbourhoods, but in others like... everything West of the downtown, e.g. towards Golden Gate Park, Richmond, Sunset, Twin Peaks, etc. was extremely barren from anything other than single family houses, with the occasional street with restaurants and shops.