In-N-Out has more than 400 restaurants.
It has four patty-making facilities.
Those two numbers are the entire company, and the connection between them is stated plainly on In-N-Out’s own media page: the company only builds stores that are located within a close proximity of their four in-house patty-making facilities, so that it will never take more than a single day’s drive for their own trucks to deliver fresh ingredients.
That is not a philosophy about quality. It is a logistics constraint, written down, and it decides which cities In-N-Out is allowed to exist in.
Which is why a chain founded in 1948 had thirteen stores by 1973, and why opening in Tennessee required $125.5 million and a 100,000 square foot building before a single burger was sold.