It’s important to keep the club shallow in order to create optimal spin when the ball lands on the green. There’s a common misconception that hand manipulation is the only way to increase spin, particularly when chipping and pitching. Although this can definitely help, it will not do so if your angle of attack is incorrect. As is my belief with 85-90% of all shots around the green, the club needs to be traveling on a shallow path into the ball. This shallow angle of attack will allow the body and club head to keep moving through impact.
In addition, overactivity of the hands and arms will create a steeper angle of attack, exposing the leading edge, often driving it into the ground at impact. This results in slowing the body and club down, reducing spin off the club face. To create optimal spin, if you keep the club wide and shallow, it’s going to prevent the leading edge grabbing the ground through impact and continue to move through the ball.
In addition to the angle of attack, your body speed is a great way to increase your spin rate when chipping and pitching. You can learn more about that here.