* It is a key driver of the plot. Enkidu is initially created as an adversary for Gilgamesh, but the two eventually become close friends. This friendship leads Gilgamesh on a quest to find the secret of immortality, which is the main driving force of the story.
* It provides insight into the characters of Gilgamesh and Enkidu. The friendship between Gilgamesh and Enkidu reveals their strengths and weaknesses, and helps them to grow as individuals. Gilgamesh learns to be less arrogant and more compassionate, while Enkidu learns to be more assertive and independent.
* It adds a layer of tragedy to the story. The death of Enkidu is a major turning point in the story, and it leads Gilgamesh to question the meaning of life and death. This existential crisis adds a layer of depth and tragedy to the story, and makes it more thought-provoking.