Squatting deep requires more than just trying to drop lower. The reverse squat teaches you to pull into the bottom position and strengthen the muscles that support full-range squatting.
A semi-wide squat stance can shift emphasis toward the inner thighs and create a different lower-body stimulus. Stance width becomes a training tool instead of a random preference.
Squats may be king, but step-ups deserve a serious place in the lower-body toolbox. Single-leg work can build muscular legs with less ego and more control.