More people arrive in the lunch hour than at other times. Simulation can model all that and more. Simulation is limited only to what you want to spend the time getting data and programming it in. You can make your model of the world include anything you want. Your data collection costs may be enormous, but you can put in pretty well anything you want.
Errors can creep in in many places.
The program written may not reflect the model. The models for the random variables may be incorrect. Every statistical test has built in assumptions that may or may not hold. A simulation would not be able to determine such results with such accuracy. The statistical nature of the output makes drawing any firm lines difficult.