What is the role that point of view plays in the novel No Country for Old Men?

The role of the point-of-view style of narration in No Country for Old Men is to give the readers differing perspectives of the characters, each of whom are archetypes. For instance, the protagonist represents the wise sage and the antagonist represents what psychologist Carl Jung called the Shadow Archetype. In a Biblical analogy, the protagonist is a prophet trying to understand the ways of men, while the antagonist represents evil in its purest form—an entity devoid of humanity.
Showing these archetypes via specific point-of-views allows the author to form a whole picture using fragments of beliefs, thoughts, and experiences like a collage. If written in a traditional narrative style, there is a chance that nuances will not be perceived by the readers. Also, the detachment style of the author shows that he doesn't believe there is any true definitions of right and wrong. For instance, one of the "heroes" is himself flawed (e.g. greedy). The POV style shows the different aspects of humanity and the psyche, thus making the story more layered and the characters multidimensional.