Simulation is a compass not GPS
It’s meant to explain that simulation doesn’t give you a single number that’s the right answer it gives you guidance of the area to look at for the solution.
It’s not that simulations can’t be accurate enough to give the exact answer.
The New Zealand Inland Revenue use their simulation as an operational planning tool and report that there is only a 1% difference between what the simulation tells them and what they see when they implement it the real world.
It just means that as powerful simulation is, it still needs a human to interpret what the results mean and make the final decision as to what is the best outcome.