Did you bother watching the rest of the video? He basically said sensor size made a difference and has a different look for his conclusion.
Think it matters much more in photos than video due to the nature of format. Video is a constant flow with story, photo is static
The demonstrations, both with the light and the shot of the teddy bear tells the story. The APS-C sensor had a more shallow depth of field with the same lens and settings and the background looked better.