By the end of the book is Pi a hero? Why is it important to make this comparison to understand the meaning of the story?

First, let us take a look at the definition of hero from a literary standpoint. The term hero has been used to simply denote the main character. As an archetype, the hero has appeared in every religion in the world. The hero archetype can also be found in mythology and epics from all over the world. Here are some common characteristics of the hero archetype:
The hero leaves his home or family.
Some type of event sends the hero on a quest or journey.
Often, the hero has a weapon that only he/she can wield.
The hero often secures supernatural help.
The hero must prove himself and overcome many obstacles on the journey.
Although there are many different versions of the hero's journey, the basic outline of the hero's journey is outlined below:
An initiating event.
A call to action.
Crossing the threshold between the known and the unknown.
A series of tests/challenges.
Return as a changed person.
Using these models to understand Yann Martel's novel Life of Pi, I would say that Pi is a hero. This assertion helps us to see the story through a different lens. It is a multilayered novel, and the events are incredible. Analyzing Pi from the standpoint of the hero's journey shows Pi as a master of his circumstances rather than a victim of them.
For Pi, the initiating event is when Pi is thrown overboard by the crew of the Tsimtsum during a storm. He lands in the ocean with several wild animals that are being transported to North America. He saves Richard Parker, the Bengal tiger, even though he is well aware of the danger he might face as a result.
Throughout the next portion of the book, he observes the actions of the other animals aboard the lifeboat without taking much action himself. He observes when the hyena kills the zebra and the orangutan. Then, he observes the tiger kill the hyena. In a way, this is Pi's call to action. Previous to this, the tiger has been seasick and not much of a threat. When the tiger kills the hyena, Pi is awakened from any complacency and knows that he must master the tiger or fall prey to it.
He masters Richard Parker by providing for his needs, establishing his territory, and using the whistle to assert dominance. This is certainly part of the challenges Pi faces. The Frenchman is also a challenge for him. Pi is desperate for companionship. He is clinging desperately to his sense of humanity and morality, things he learned while practicing the three world religions he identifies with. Instead of existing as a companion or mentor, the Frenchman turns out to be an enemy and is disposed of by Richard Parker.
The next challenge Pi faces (in addition to the challenges of daily survival with the threat of a Bengal tiger aboard the lifeboat) is the island of the meerkats. At first, it seems that Pi has found a type of paradise. There is fresh water, an abundance of food, and shelter. However, he learns that the island is carnivorous, and it is one of the biggest threats he faces. Along the way, he turns to prayer, which is where the supernatural intervenes on his behalf. He prays to Allah, Jesus, and a Hindu god.
The end of the story includes Pi's return to civilization. He tells the story of the animals on board with him, and investigators refuse to believe it. He then tells the exact same story with humans in the place of animals. Investigators are left with the choice of which version to believe. For Pi, his transformation has come through the trials he faced. He feels a sense of loss that Richard Parker leaves him without a thought, which shows that Pi's humanity is intact. What is changed in Pi is the confidence he now possesses: he is able to face up to anything he encounters in life. Readers are faced with the decision of which story to believe. The one with the animals could be a manifestation of the trauma that Pi went through. The version with the humans could be the truth, or it could be told to satisfy the investigators. Other changes that take place in Pi depend on which version readers choose.