One of my gurus, Vince O'Neill, liked to demo using slugs out to the 200, and could hit at that range on demand. As noted, one has to put in the work.
Some of the guys on the video posted by the OP appear to need more time on the gun. A common "malf" I see when people run a pump gun is that they pull back with both hands hard and ride the recoil, which then causes them to have the action locked.
As Tom noted, the vast majority of shotgun incidents are a one round event. I am a big fan of rifles, and ARs in particular, but I have never seen one take a human being's arm off at close range. I have seen a 12 gauge do exactly that, with a single round.