Dragon Ball Z introduced the son of Goku, Son Gohan, to many fans at the time who didn't have many expectations for Gohan's involvement in the story. However, as time passed, we have witnessed flashes of strength from Gohan ranging from harming Raditz considerably in the first arc, all the way to his recent new transformation where he relived a moment that solidified his success in the eyes of many fans. However, that doesn't mean there weren't many valleys that sidelined Gohan so many times before, from his defeat at his own arrogance in the Buu Saga, to his complacency and disrespect at in the Resurrection F Arc. However, it is interesting to understand what about these peaks and valleys make Gohan an integral character to fans of Dragon Ball and the ideals that Gohan represents.
Son Gohan is many fans favorite character from Dragon Ball Z as a result of his big moment's over the course of the Saiyan Saga, Freeza Saga, and Cell Saga. Even more so when Gohan finally achieved Super Saiyan 2, which resulted in his best moment as a character and fighter at a very young age, becoming a great inspiration to many fans watching Dragon Ball Z at the time. Still, it doesn't change the fact that many consider this to be the moment that Gohan's character peaked and steadily declined from there. However, there also is enough reason to see Gohan's continuous peaks that return after the Buu Saga and even in the Dragon Ball Super run. After all, as a character he improved from being a conflict-averse child to a responsible adult, so it's really a matter of understanding how these peaks and valleys really happen and why they matter.
Why Gohan Succeeded
To understand Gohan's peaks as a character, one needs to go back to his beginnings as well as the arc he underwent through the first two arcs. Despite his rocky start in the Saiyan Saga, Gohan needed to be a meek, cowardly young child at first to further highlight his moments of bravery when rage overtook him and his power spiked against the enemy. These highlights built suspense for the audience, hooking their attention to the screen and wanting to learn and understand how will Gohan grow over the course of the story. The Freeza Saga in particular did a good job of showing this by the end, that he becomes more active and less cowardly against the enemy soldiers; Gohan's steadily rising peak and popularity at this point in the story wouldn't reach its peak until the next arc.
Gohan Vs. Perfect Cell struck a chord with so many individuals because of all the built-up from the prior two arcs that established Gohan's potential for power and strength, which paid off when he transformed into Super Saiyan 2, and demonstrating how his power dwarfed Cell's by a magnitude greater than what everybody could ever think of. While it came at a cost, Gohan eventually defeated the foe that not even Son Goku could defeat and proved himself a favorite for many fans of the show as a result. And for a while it seemed that the series would end on this high-note for Gohan's character. If the story ended right there, then Gohan would have had the biggest peak as a character. Of course, the story of Dragon Ball didn't end there and neither did Gohan's story, even with the following flaws as well.
Understanding The Failures
Despite all of Gohan's successes in Dragon Ball Z, and some in Dragon Ball Super, it isn't fair to neglect the valleys or moments where Gohan's character either stagnated or felt like he was regressed. Soon into the Buu Saga, Gohan was revealed to have been out of practice due to the time of peace, and by the time he achieved his Ultimate Gohan form, he had a peak followed by a sudden drop. Because soon after that, he gets absorbed by Super Buu, and cuts his time short in the story. It only becomes more apparent during Dragon Ball Super, where in the Resurrection F Arc, he's become weaker than most of the enemies and kept struggling even against those he used to be able to deal with no trouble. Gohan's state after powering up and releasing KI to give Goku an energy signature certainly shocked many fans, many surprisingly considering this the moment Gohan is at his lowest.
And for the most part, this was the way it has been for a long time. Until Dragon Ball Super: Super Hero came, we didn't get any new development for Gohan until this movie. And as a result, we not only got some much deserved respect for Gohan's character as well as his mentor Piccolo, the fans were treated to a new transformation named Gohan Beast that is rumored to have put Gohan back into the playing field with Goku and Vegeta. Gohan's peaks and valleys always seemed as if they were going to be final, but the major thing to focus on is that they were a response to the fans disappointment and excitement of Gohan's character throughout the years. Overall, Dragon Ball Super will improve in both Manga and anime, so long as they remember to not neglect Gohan's development and bring him back to the forefront of the show; along with giving him some much-needed respect that many fans could be excited to see and feel in the future.