Why is the highest realm of calligraphy "scattered" and "light"

Personally, I think that the art of calligraphy pays attention to the combination of Yin and Yang, and the word "Yi San" corresponds to the word "regular script", but from the perspective of layout, it is the opposite, and the effect of layout should be full. The word "Yi Dan" corresponds to the ink painting method, because the color contrast can stand out, and the change of color brightness will have a three-dimensional effect on the whole work, which can better reflect the brushwork and emotion.