A resume is not soulless. If it is soulless, then a video is even more so.
Also, video is a horrible medium for most people. It takes time and effort to be good on video. Good developers may have spent their time and effort elsewhere. I would point to Ryan Dhal's nodejs regrets video on the front page as an example.
Kind of like Instagram lifestyle curation because everything in your life must be a photogenic and epic Big Deal That Makes You A Somebody.