It's not just about what they can use the video for. This also lets them screen for a lot of protected classes without actually asking about them. Your name and resume don't convey your skin color, your accent doesn't come out in your work history, nobody can make guesses about your sexuality based on your work email address, but these all become much more easy to discriminate against with a video. All under the pretext of "We didn't like their answer to the question."

And you don't even get the context of an interview to defend yourself.