I've always been told that no matter what you do, this type of artwork must be done by hand. If you take a video clip and try to quantize it, it just won't look

I've always been told that no matter what you do, this type of artwork must be done by hand. If you take a video clip and try to quantize it, it just won't look the same. Same with all pixel art. Cannot be automated even though it is tempting to think it can be. How true is this?