Sun Wukong also understood this principle. If it were so easy to complete the Earthly Dao and the Human Dao, how could it have dragged on until now unresolved?
Just looking at the Emperor's previous sighs, one could tell there were many hidden issues. Besides the challenges inherent in completing the Earthly Dao and the Human Dao themselves, there were likely endless struggles from all sides and probably even issues with the stance of Daoist Ancestor Hong Jun.
He continued to read the following replies.
Du Xiu gave a major hint, "There were indeed mighty beings who tried, such as the Ancestral Witch Houtu, who transformed into the cycle of reincarnation, but the six paths of reincarnation she established were not complete, so the Earthly Dao was incomplete.
Lady Nuwa created humans, presumably to complete the Human Dao, but she also did not accomplish the goal of completing the Human Dao."