Because they want to get under those 3 minutes per patient limit.

But for real - if you want to quality things a scale is needed. Otherwise might as well use any description, including showing with your hands “how much”.

Thats why I describe the scale to the doctor, eg ‘with 10 being fainting from pain, 9 being unable to function or willing to die, etc etc … my sudden short term pain is at a 6’.