The narrative of One Piece is incredibly vast, teeming with a plethora of information and an immense cast of characters.
It has been 26 years since Eiichiro Oda's manga began serialization and 24 years since the weekly anime release. To date, One Piece has reached the milestone of 1100 chapters and over 1000 episodes. Despite Oda recently mentioning his spiritual child would conclude in three more years, predictions about the length of the series always remain 'far from over,' considering the deep and extensive storyline still in existence.
The story of Monkey D. Luffy, the wielder of the Gum-Gum Fruit, and his dream of becoming the Pirate King has captivated generations. Luffy's journey includes adventures on numerous islands, clashes with the Navy and the World Government, as well as encounters with the Four Emperors of the sea, all incredibly engaging.

Initially, Oda planned for One Piece to only last 5 years. However, the narrative expanded beyond expectations due to the introduction of the Shichibukai, a crucial group of characters in the story. Before facing off against figures like Kaido and Big Mom, two powerful Emperors in the New World, Luffy had to deal with the 'sub-bosses' among the Shichibukai, which was never part of the plan.
The Shichibukai are former pirates granted amnesty for their crimes and serve the World Government. While the members of this group change throughout the series, there are always seven. Interestingly, Oda's inclusion of the Shichibukai in the storyline was a later addition, extending the narrative beyond the initial plan.

This development has led to epic clashes like Luffy's battles with Crocodile in Alabasta, Gecko Moria at Thriller Bark, and Donquixote Doflamingo in Dressrosa, among others. The additional characters not only bring about magnificent fight scenes but also solidify Luffy's growth and enrich the universe of the series. Concurrently, it significantly extends the length of One Piece.
Oda admits that One Piece was initially conceived as a 5-year story, with the main focus being the showdown with the Four Emperors. However, the spontaneous introduction of the Shichibukai into the storyline is the primary reason the series hasn't concluded yet. Oda acknowledges that he should have limited this group to 2-5 members instead of 7. The author expresses some regret.
The presence of the Shichibukai was introduced early in the series, in the Baratie arc, where Sanji joined the Straw Hat crew and Dracule Mihawk was introduced. Initially, Oda didn't anticipate how many members this group would have, inadvertently expanding the organization's scope.
Nevertheless, the existence of the Shichibukai also brings positive elements, such as Jinbei joining the Straw Hats and the introduction of some of the most memorable antagonists in the series.