There’s a difference though. Doctors are trained professionals so when they kill someone it’s by accident (hopefully), but quack doctors are not professionals, when they kill someone it’s 3rd degree murder.
There’s a difference between making stuff up and an unsuccessful medical procedure, but the only way to tell the difference is if the person has a reasonable chance of actually being successful I.e. a medical professional.
That’s why surgeons don’t commit assault. But some random person coming at me with a knife does even if the end result is still my chest cavity being opened up.