Why are people who are good at simple things not easy to understand?

Confucius said that "those who are good at the Book of Changes don't predict", which can't be understood as "those who really understand the Book of Changes will never use the Book of Changes for divination". The Book of Changes was originally invented by the ancients for divination. If people who know Yi-ology stop divination, Yi-ology is meaningless and has been lost since ancient times.

The generally accepted understanding that "people who are good at barter don't predict" should be that people who are really proficient in barter can see destiny, and they also understand that since it is destiny, human resources can't be changed, so divination is actually dispensable for these people themselves.