I always thought you shoot to kill or don’t shoot at all.
But you dont have to fire a defensive weapon to use it to save your life or someone elses. More often than not an attacker will be persuaded to leave at the sight of a firearm.
Outside of just practice on the range, that is my stand.
Shoot to stop. That may be achieved by killing, but the goal is to stop an attack. When the threat ceases, you cease shooting.
The problem with “shoot to kill” is that becomes your goal ... and if the attack stops and the threat ends but the assailant is still alive, your preset auto-pilot goal will be to continue until he’s dead - and that’s murder.