Throughout the course of One Piece, Luffy’s goal has always been made out to be attaining the title of King of the Pirates. As the story of One Piece evolved and grew progressively deeper and deeper, the significance of that title has somewhat changed.
While Luffy certainly still wants to be Pirate King, the title is no longer the end our protagonist is working towards. The title of Pirate King has evolved to become something that is used to achieve what one wants.
Even Luffy has a goal beyond One Piece’s Pirate King title which necessitates being the Pirate King to achieve.
One Piece’s Pirate King title isn't really the series’ endgame, it's more of a means to an end
Why is the Pirate King title not the end goal?
Throughout One Piece, the title of Pirate King has been built up during the entire series as the final goal of the Grand Line journey. Yet even the Four Yonko, who’re closer to it than almost every other pirate on the sea, have goals beyond the Pirate King title.
Big Mom, for example, has two major dreams which can be completed with the Pirate King title: for everyone in the world to be at her eye-level, and to create a nation where all races live in harmony. Both of these goals require levels of power and influence which only the Pirate King can attain.
Kaido also has an objective which lies beyond the Pirate King title. Kaido simply wants chaos and war to ravage the One Piece world, since (as he’s self professed) he’s grown bored with the world. Being the Pirate King gives him the clout and power to instigate this world war, especially if he successfully keeps control of Wano.
Similarly, Blackbeard also seems to want chaotic destruction as his end goal in Once Piece. Neither of these three Yonko have ever mentioned a true, innate desire to become the Pirate King. If the Pirate King is defined as being the freest in the sea, then really all three of these Yonko have missed the mark on what to do with the title.
Shanks is an interesting case, however. Shanks realized long ago that becoming the Pirate King means becoming greater than the Pirate King. That is to say, whoever becomes the next Pirate King has to become greater than Roger was, and greater than what he did for the world. Upon meeting Luffy, Shanks realized the young boy had this potential and chose to guide his life into becoming what he was meant to be.
By understanding this fact about being One Piece’s Pirate King, Shanks also recognizes he isn’t the one to do this. By knowing the journey after the journey, Shanks also knows he can’t accomplish what must be done.
Luffy’s goal in being Pirate King has always been being the freest on the sea. When Luffy finally reaches Laugh Tale and learns the true history of the world, he’ll want to ensure nothing like that can happen again. The Void Century will undoubtedly touch on topics which are inherently freedom revoking. As a result, he’ll become greater than the Pirate King by becoming the one who liberates the entire world from the World Government and their tyranny.
No other Pirate King candidate has this passion for freedom that Luffy does. Blackbeard has been shown to have almost no moral qualms with any aspect of life. Kaido and Big Mom both have slaves. Kaido has the Udon Prison prisoners, and Big Mom has her book of races in which she entraps people from unique heritages.
As a result, Luffy is the only One Piece character fit to become the Pirate King. To be the Pirate King is to be a trailblazer, like Roger was. Yet Rayleigh says he and Roger were too early, and they weren’t the ones Laugh Tale was waiting for. Luffy is the one who will trailblaze beyond the foundations Roger has laid, and in the process will prove One Piece’s Pirate King title is not and has never been the journey’s end.
In summation
One Piece’s Pirate King title has driven the motivation of so many different characters, yet the title itself is just a means to an end. One Piece has evolved beyond the Pirate King endpoint, leading to the title becoming something used to accomplish one’s true goals.
To be the Pirate King is to be a trailblazer, and whoever the next Pirate King is must surpass Roger in that way. When Luffy becomes One Piece’s next Pirate King, he’ll prove why he’s the only one who could do it by truly surpassing Roger and making the seas 100% completely free.
Be sure to keep up with Luffy’s journey via the official weekly release of One Piece chapters on various Shonen Jump platforms.