This is actually covered in the video. It's the "we should use a chromatic scale" argument and is surprisingly old.

The answer to why people don't use a chromatic scale is also in there. Very roughy, it's harder to sight read intervals between notes.

Standard music notation is a like a London Underground map, it's symbolic rather than literal.

Being more symbolic gives standard notation many advantages once you learn it.

The video does a much better job of explaining that than I've given. It really is very good.