What is the effect of the phrase "vegetable existence" on the meaning of this passage?

It shows that the narrator prefers life in the city over life in the mountains or wilderness.
It demonstrates that the narrator sees his life as useful and fulfilling compared to the Cabuliwallah's life of aimless wandering.
It emphasizes that the narrator sees his life as dull and inactive compared to the exotic and adventurous life of the Cabuliwallah.
It clarifies that the narrator prefers a steady life in a familiar environment over travel.