Sometimes a simulation IS the thing. A simulation of a wall clock IS a functioning clock (e.g. the clock icon on our smartphones). An autopilot that can takeoff, fly, and land an airplane IS a pilot. Chess engines that can beat grandmasters are chess players. A computer simulation of a teacher that can educate students is a teacher. Sometimes these simulations lack some of the capabilities of their human counterparts, and sometimes they far exceed them.
> You would not expect your computer to pee on your desk if you were to simulate kidney function, would you?
You would not reject a computer-controlled dialysis machine as "just a simulation" if you had kidney failure would you?