Myself I don't have the time to watch or listen to as much as I can read and that is probably true for the non-dyslexic 75%.

Disagree. Video+audio is too information-sparse to give any sort of actual insight into those things. Unless the video were many hours long, maybe.

I'm also pretty sure that nearly nobody will devote the time needed to watch the video unless they were very interested in you to begin with.

Job application processes are more about compliance with internal procedures for evaluating candidates than they are about the capabilities of the candidates themselves. Exploring better ways to verify a candidates capabilities are outside the scope of most HR departments.