Very often the benefit of focus is passed by in the name of satisfying the broadest possible audience. What's lost is the quality. The specialized or niche chow joints are owner operated, zealous about what they do, and always narrowly focused.
Neighborhood small wine shop: The Wine Thief, thoughtfully narrow selection, zero attitude
Coffee shop in the barrista arts category: Kopplin's, great equipment and dedication
Old school sandwich shop: Maverick's, proper roast beef and braised meats (happens to be next to a Subway franchise, ideal for the compare and contrast experience)