Videos overcome everything else on a webpage. You can either read content, or watch a video at a time. Also, many times before I play a video, I grab my headphones and plug them in. So surely from a user’s perspective, videos shouldn’t auto-play. Background videos without sound seem to be okay, without considering how good or bad having them is.
Sydney Morning Herald does delayed auto-play. While the video is related to the content, its immensely distracting. I start to read an article, and then the sounds from the video (playing at the top of the page and not even in the viewport) always make me frantically find the stop button.
I find videos interesting when the write-up builds up the story and creates a reason for me to watch them.