What is the function of chapters 8-10 in into the wild?

Krakauer expands on the theme of intrepid explorers that have preceded Chris.

Another young man, John Waterman, is often compared to McCandless. He was a very talented young climber with a troubled relationship with his father, a tragic personal life, and a very eccentric personality. He became more and more unhinged, and eventually embarked on a borderline suicidal climb of Denali, during which he disappeared, and is presumed dead. Carl McCunn is also often compared to McCandless. He was an amateur photographer from Texas who moved to Alaska in the 1970s, and in 1981 arranged to be flown into the wilderness for five months, where he planned to mostly shoot pictures of wildlife. He forgot, however, to arrange to be picked up, and so ended up killing himself as he slowly and painfully starved and froze to death.

Everett Ruess was another figure who can be compared to Christopher McCandless. He was born in 1914 in California, and went on his first extended solo trip hitchhiking and trekking at the age of sixteen. With a few short exceptions, Ruess would spend the rest of his life on the move, living out of a backpack with very little money, often sleeping outside and making due with little food. He wrote many letters while doing this, which show his intense passion for nature and natural beauty. Chapter ten focusses on Chris's body being found.