You may have heard some different perspectives of bar placement during the squat. Allow me to clarify some things for you.
Low Bar Back Squat - the bar is lower on the traps, your hands take a wider grip and your elbows flare out and back. The elbow flare is for flexion of the rear delt and acts like a little shelf that locks the bar in place.
See how the bar is mid trap and resting on the back of the delt? Doesn’t look comfy, but that’s just my opinion.
Now that we have position covered, let’s review it’s movement. You’ll most likely see 100% of powerlifters using the low bar back squat because their goal is to hit parallel and nothing more. Anything more is unnecessary. It’d be like trying to win a superbowl by passing it instead of running it with Lynch in the backfield. Dumb. In powerlifting, parallel is all that’s necessary with as heavy a load as possible.
Low Bar allows you to stop right at parallel because its placement on the spine. It’s placed lower, so in order to stay on the midline of the body (and maintain center of gravity), you need to lean forwards. This shoots the hips back and out with minimal knee bend.
We see here that low bar (on the far left) has a more down facing chest position and doesn’t allow for maximal depth.
High bar back squat (demonstrated in the middle) allows for a much deeper movement, upright chest position, closer grip on the bar and all around better looking movement. Your wrists aren’t is a cocked back, awkwardly extended position and you don’t have to worry about looking like a newb because you missed full depth.
Now, they both have their benefits and if i were going to a 1 rep max in competition at a powerlifting meet, i’d train low bar. But I hit snatch and clean on the reg so high bar best serves my goals. Lastly, increase range of motion improves muscle hypertrophy (growth). So if you couldn’t give two shits about strength, then squat lower, stretch and challenge the muscle. Don’t cheat yourself out of reps. You only have so many you will perform in your life, then you die. Die with huge quads.