If you give someone a hunk of metal that can take a life with a flick of a finger, the first step should be to train them how to use it. Otherwise why the fuck are you arming them?

Like, literally the first thing you learn about gun safety is that you don't point it at anything you don't intend to destroy. If a cop is pointing a gun at you, they are prepared to kill you. They are armed because if you don't shoot first, you're fucked.

Also, good luck hitting a stationary target with a gun without training, it's not that easy. Hitting a moving target (without formal training) is extremely difficult, hence you you shoot for center-mass (aka the big rectangular part of the body that's easy to hit). Nobody is shooting to disarm, if they're pushed to the point of needing to shoot, the suspect's life is already forfeit. It's why they shoot this dude when he's on the ground when he shows that he hasn't "given up". If someone is considered enough of a threat that the need to shoot at them, they aren't shooting at the legs, you aren't shooting to disarm them, you're shooting to stop the threat and whether they survive or not doesn't really matter.

Whether you like or don't like how police respond to threats, just understand: If they use a gun, they literally are incapable of taking the suspect down without the intent to kill them.