Furthermore, the presence of mortal aura is a constraint.
If one does not cleanse away the mortal aura, after becoming an Immortal, the practice of cultivation will become doubly difficult. Given the same cultivation environment and conditions, two cultivators of the same aptitude, the one in the Land of the Four Pillars will undoubtedly find it easier to cultivate three hundred years of Dao than the cultivator in the Mortal Realm.
In the explanation of the young girl "Alu," having mortal aura is akin to living in a barren land, while being without mortal aura means dwelling in a land of abundance.
To compare cultivation to earning money, the latter is undoubtedly easier to earn the same amount.
The former might not be able to earn it even if they exhaust every effort.