People's actions are mostly driven by various kinds of desires.
Eating can be said to be one of the important innate desires of human beings, a prerequisite for survival, and many of human actions are driven by the need to eat, to act in order to eat.
The practice of Taoist arts, the pursuit of the Heavenly Dao, the striving for realms, and even all desires for power and knowledge are major driving forces that get cultivators to act.
It can be said that aside from emotions such as responsibility and dreams that are not desire-based, the actions of most humans and cultivators are primarily driven by their own desires.
When Zhou Bai wiped out the desires for both eating and power, both Yan Shan and Meng Ruocun seemed to lose their life goals all at once, their entire beings radiating a sluggish aura from the inside out.