Though the Ancestral Land could provide, if all the generated Chaos vital energy was given to the Innate Dao Sovereign, what about the remaining powerhouses?
Therefore, the Human Emperor would find ways to relocate a portion of the strong from the Ancestral Land every once in a while to alleviate the pressure on it.
But to relocate people, there needed to be a reason; it couldn't be done without any cause. Expanding territories for the Human Race became the perfect pretext.
As for the reason behind enfeoffment in later days, it became even simpler: the land was conquered by them, so naturally, it should belong to them.
The Human Emperor's conferment of nobility titles on the lords was simply taking advantage of the situation, providing each lord with what was due to them.
Whoever conquered the land, it belonged to them! This is the origin of the earliest nobility.