In any epic adventure story, the main character (the hero) must go through various stages or ordeals that allows the reader/viewer to see the hero take on adversity and come to a rewarding change at the end of his journey.
Does LOST fit into this epic story telling format?
If Jack is the centerpiece character for which the LOST universe, what was his journey all about?
First, there was nothing harsh about Jack's background. He came from a wealthy home. His father was a highly compensated surgeon in Los Angeles. He did not have any real obstacles growing up. He did not have the issues of a poor child facing daily adversity in the inner city.
Second, Jack's home life is typical for that socio-economic class. When a father works hard in a hard stress occupation such as medicine, there is some disconnect between father and son. Jack was an only child so that could have added pressure on him to succeed. It also would possibly cause some isolation since he did not grow up with siblings to interact with on a daily basis. But being an only child in an upper middle class family in itself does not cause "hardship" usually associated with a hero about to take a life changing journey.
Third, Jack's personality apparently was to be competitive with his father. Jack took it personally that he had to be as good, or better, than his father. Jack followed in his father's footsteps, including working under his watch at the same hospital. He never broke the parental bond, even in his career path. This shows that Jack at some level is insecure. This insecurity could be the result of his comfortable upbringing.
It is not that a person in an easy lifestyle can be the center of a personal conflict. For example, Dan Akroyd's character in Trading Places gets his world turned upside down, from country club to poverty, caused not by his own actions or behavior but at the mere whim of his alleged mentors. But Jack never gets turned inside out by an out-of-character situational change. As a spinal trauma surgeon, he takes on matters of life and death on a daily basis. The bloody aftermath of the plane crash would not be outside the realm of his past experience in coping with the human condition.
Fourth, Jack's position of authority never truly changes after the 815 crash. Despite the appearances and flashback statements from his father that Jack lacked leadership qualities to make life and death decisions, Jack as a surgeon is the captain in the operating room - - - everyone on the medical team would follow his instructions and lead in treating a patient. So it is not realistic to believe that Jack did not have the leadership skills to take charge in an emergency when 815 crashed on the island. The proof is that the survivors immediately gravitated toward him because he took his instinctive action in helping other people. Again, this is not a revelation for a physician.
So we have a talented surgeon thrown into a medical emergency situation which he handles like any other competent physician would in a code red emergency room triage. Instead of a clean hospital, the setting is on the sandy beach of a tropical island.
Fifth, what was Jack's "true" island ordeal? At first glance it seems a simple question. But it hard to answer. What were the bad things thrown at Jack to solve? There were many injured people - - - which is normal based on his medical experience. He treated the people as he found them so that was not an "ordeal" but another day at the office. There were many scared individuals in shock after the crash. Again, he deals with people in shock all the time. Then, there is emotional state within the group to do something to help rescue - - - but Jack, in treating accident patients, had experience dealing with emotional family members who ask difficult questions. The only "burden" placed on Jack in the first days after the crash was the role of "group leader." Again, Jack was used to giving "orders" to stabilize a patient's situation. It really would not be a big stretch for Jack to use his knowledge and experience to stabilize the beach survivors into work groups. In fact, he solidified his role with his "live together or die alone" speech.
The role that Jack now plays is a father figure. Why that would be an emotional burden on his soul is stated in the estranged relationship he had with his now dead father. He never had the opportunity to set things right with Christian. Jack was the cause of his father's fall from grace (but from a medical-legal basis, Jack's career should have also been over as he was part of the "cover up" of Christian's errors). Why Jack would fell more "pressure" as an island leader is not really clear. He would get into paternal type conflict with other group leaders, such as Locke, but Jack's character never changed as a result of these strategy conflicts.
Six, if the burden on Jack's soul was his decisions causing other people to die on the island, then it was a burden shared by all of the survivors. Jack's decision to move to the fresh water of the caves saved the survivors from an early demise, but that important event was orchestrated by the smoke monster in Christian's form. Jack continued to chase the fake ghost of his father from the moment he left Los Angeles until the moment he closed his eyes for good in the island bamboo forest.
So if Jack's entire journey was one of self-reflection on his strained relationship with his father, that seems like a weak foundation for a six-year long series. Further, he never truly resolved his relationship issues with his father. He never broke the bond of his father's shadow because at the end, he needed his father to guide him to the next level of existence.
Jack's island life mirrored his previous life as a surgeon in LA. Jack's role as a leader of the survivors was not that much different than his role as operating room leader. The only change to Jack was the "guilt" of leaving people behind after the O6 rescue. This guilt drove him to drinking and drug use. Why this guilt of leaving people he only knew for a few months behind would drive him nearly insane is hard to believe. And the only way to resolve his guilt is to go back to a hellish island prison seems illogical for a man of science. Is the personal toll that the guilt inflicted on Jack (by his own hand) the adversity that a real hero needs to overcome for the greater good?
Probably not.
But then, viewers will state that Jack's personal sacrifice of himself to be the temporary island guardian (which cost him his own life) was needed to save his friends. But if you look objectively at the facts, most of Jack's "friends" from 815 were dead (Locke, Jack, Charlie, Jin, Sun, etc.) The only people allegedly "saved" were Kate, Sawyer and Claire - - - but it was Frank, as the pilot, that actually got those people off the island (rescue), not Jack. And Rose and Bernard were not "rescued" by Jack's demise - - - they were content to be left alone on the island. So what did Jack's death accomplish? It punted the responsibility of the island to Hurley. But does a hero delegate his role to another lesser character to finish the task? It was Hurley, through Desmond, through Charlie, that awakened the souls in the sideways world, not Jack. Jack was literally the last person to the after life party.
So when commentators believe that the LOST story was all about Jack, then what was Jack's story resolution? In the end at the church, there was no great moment of remorse, apology or understanding with Christian. It was just a light bulb moment that Jack realized that he was dead, that everybody was dead. If the message is that death solves all human problems, then Jack's story is not unique.
Jack as a hero figure went through many missions and conflicts as the leader of the 815 group, but those events and adversity never truly transformed Jack into a different human being or allowed him to gain a special insight that he was lacking before his adventures began. And his reunion with his father at the church was anticlimactic. It did not solve any of his daddy issues.
The only thing that occurs at the end is that the other people in the church "waited" for Jack. They waited for him to realize that he was dead in order for all of them to move on in the after life. At best, they believed that Jack was the glue that kept their group together. At worst, it was a plot device to create a happy ending. One could argue that all the people in the church led very lonely lives. The greatest moments of friendship, for good or ill, happened because of the crash of Flight 815. But that is not an epic heroic journey, but more like a nursery rhyme.