I've attended many hospital births. At every birth I attended except one, all the doctors were very hands on, stretching vaginal tissues as baby's head came down, reaching hands in to grasp baby by the shoulders to bring baby out, or worse yet, placing both hands on either side of the baby's head and applying traction to pull baby out. These were births where there were no indications the baby needed any help to get out.
Being hands on, intervening in the physiological process of birth, can have negative impacts. Pulling on a baby's head can cause nerve damage to the shoulders, and/or face. Placing hands in to stretch tissues may actually stress and weaken the tissues compared to letting them stretch gradually around baby's head. Placing hands in to pull baby out by the shoulders can lead to tearing when there normally wouldn't have been tearing or it may make a tear worse.
There are times I need to use my hands to help baby navigate its way out. A shoulder could get hung up on the pubic bone, or baby's torso could be larger than the head leading to the need to help baby out. Often in those situations, simple position changes to open the pelvis in different ways are all that is needed to help baby out. It is rare that I actually have to use my hands to help baby. In fact, I have only needed to use my hands to help baby out twice in the births I've attended in my own practice so far.
I firmly believe birth works best when it is not interfered with. I am mindful of this at every birth I attend. I don't want to disrupt physiological birth unless baby lets me know they need help, and then using an intervention that involves my hands is a last resort when other options have not worked. Balancing my knowledge, and intuition with trust in birth helps me keep my hands off unless there truly is a need to use them to help baby.