Just to provide an alternate opinion, here’s what Greg Nuckols says in his squat manual:
"Once you reach the sticking point, your goal should be to make it through as efficiently as possible.
The biggest mistake people make at this point in the lift is panicking and rushing themselves. When this happens, they’ll let their hips keep rising without the bar moving very much. The net effect is that, even if they made it to the sticking point in a good position, they’re putting themselves in a less mechanically advantageous position, so they’ll have to finish the lift as a good morning (if they finish it at all).
The better strategy is to continue driving your traps back into the bar aggressively, while simultaneously trying to drive your hips under the bar. Your knees will probably shift forward as well.
This feels almost like locking out a deadlift. In a deadlift, when the bar passes the knee, people are cued “shoulders back” and “hips forward” to keep their hips from shooting up higher and to make the lockout much smoother and more efficient. Those are precisely the same cues you should use to get through the sticking point of a squat."
…(referring to a graph and a few studies)
"By trying to drive your hips back under the bar, you decrease the demands on your hip extensors, which are near their limit, and increase the demands on your quads, which can handle more of the load. This ensures that the load remains evenly distributed between the knees and hips to make the lift as efficient as possible.
Though it’s subtle, this video shows this technique well:
I rest my case.