Medicine in the Spiritual World
Alchemy, in general, could deal with various anomalies in the cultivators' bodies by combining different ingredients to produce spiritual pills.
However, such actions were not carried out overnight and needed years of knowledge accumulation. And even when a prescription for a pill was ready, there might still be no supply of the necessary ingredients.
Because of this, more specific pills, which could treat less frequent anomalies, were much more challenging to obtain.
Consequently, in this space left by alchemy, medicine had emerged and gained space in the Spiritual World.
Not everyone could afford the scarce spiritual ingredients of pills. Even when they could, such resources were limited and rare to find. Therefore, people needed an alternative, which could depend less on items and more on people.