The simple thing that I think is missing here is that you can squat in an upright position with your knees in front of your toes or with your torso forwards wit

The simple thing that I think is missing here is that you can squat in an upright position with your knees in front of your toes or with your torso forwards with your shins vertical (or anywhere in between). And both are okay! What you can't do is vertical shins and vertical torso! As you sit more upright, your knees have to go forwards (past your toes) for balance. Kelly Starrett: https://m.youtube.com/watch?v=4QJ36zMt5bc https://m.youtube.com/watch?v=4QJ36zMt5bc