Okay, In-N-Out does a great job. But a Taco Bell kitchen is about the same size, yet produces a substantially larger menu.
How do they pull it off? Middleware. At In-N-Out, they make food out of potatoes, buns and refrigerated beef. At Taco Bell, they make food out of ingredient bags which are processed and packaged off-site. In-N-Out is something that a chef can respect -- Taco Bell is not.
But it's worth pointing out that In-N-Out can thrive only because their market doesn't demand a wide-ranging product. Sometimes markets move in that direction, and the artisans -- who cannot abide using middleware, who want to make everything to their high standards -- have a hard time competing.