Face Washing?

The Senate confirmation hearings over presumptive CIA head, Mike Pompeo, have reopened the waterboarding controversy.
A little research will show that waterboarding is an ancient, widespread, practice. Surely, if only by accident, at some place and time a recipient of waterboarding has died.
The claim by many in the U.S. government that this practice is merely "virtual torture" has me asking two questions:

1.) If one of our prisoners were to die while being waterboarded, would he be "virtually dead"?
(Despite the current zombie craze, for argument's sake let's define a dead person as someone who has stopped moving and breathing and will stay that way.)
Now, since a person can fake death for only so long, it seems that we would be faced with an actual corpse that was produced by virtual means. We would have to conclude that a simulated procedure, if applied too vigorously, can have real results. Perhaps if the race car you're driving in a video game crashes too many times, you could actually get a concussion. Who knew?

2,) But here is the really important question--one that I have never heard asked:
If waterboarding isn't torture, WHY DO IT?
A prisoner is taken from his normal cell and brought to another place (the non-torture chamber?) where specialists proceed to not torture him for a while. WHY? Exercise for the guards? Relieving boredom? Washing the prisoner's face?
If the object is gathering information, why not just go to the prisoner and ask him what you want to know? Of all the methods of interrogating a prisoner without torturing him, what's so special about waterboarding?

Quite simply, if waterboarding isn't torture, WHY THE BLOODY FUCKING HELL WOULD ANYONE BOTHER DOING IT?!