Why didn't Liu Yi use the hexagrams in the Book of Changes? How did Zhou Wenwang occupy it?

The hexagrams in the Book of Changes are only used when they are used like hexagrams. You can go to Shao Yong's The Book of Changes of Plum Blossoms in the Northern Song Dynasty, where teenagers are happy and the elderly are worried, and so on. All the words of the Book of Changes are used there. In addition, tapirs and tortoise shells were also used in ancient times. The hexagrams obtained by other methods are generally not used. Six hexagrams belong to the acquired divination method, which only existed in the Han Dynasty, so there is no need for divination, only looking at the restraint between six hexagrams and the influence of the sun and the moon.