The Right Foot Back Drill works so well because you can get your hips out of the way, and it gives you the space for your arms to swing down into the ball.
When you drop your right foot back, it makes it easier to time the outside circle of the clubhead with the circle of your center as you go into the ball.
Many Tour Players will drop their right foot back to hit the ball harder. Doing this gets their hips out of the way, gives them more time to hit the ball, and gives them a more significant turn.
Hitting the ball with your right foot back allows you to hit the ball farther and be more consistent. The only downside is that your swing path might might follow your foot line. Whether your feet are open, square, or closed, your shoulders and eye line stay the same.
Moving your feet allows your lower body to do different things, and that’s why players adjust their feet. This lets you do other things with your arms.
The Right Foot Back Drill is excellent; everyone should learn to do it.