I'm not sure how many people actually pay attention to the video if they've seen it, either. True, you can't use the IFE screens while it plays, but that does nothing to stop you from putting your noise-cancelling headphones on and looking at your phone the entire time. Personally, I pay more attention to flight attendants because I find ignoring them while they're standing up there to be rude. Never hurts to hear the information again and again (even though I could probably do the demo PA at this point); the more you hear it, the more likely you are to remember what you need to do in an emergency.. Can't help people who aren't willing to pay attention to something that may save their lives, though.