The infamous Gomu Gomu no Mi, also known by its true name Hito Hito no Mi, Model: Nika, plays a significant role in the story. Recently, One Piece has revealed details about Luffy’s devil fruit, which is connected to the legacy of Joy Boy. Consequently, after Luffy awakens his power, many people begin to refer to him as Joy Boy.
Luffy and Joy Boy share a dream, yet there is another character in the One Piece world who also experiences a similar dream: the Pirate King, Gol D. Roger. It is well-known that both Roger and Luffy are strikingly similar, and Oda has clarified this point several times. However, the Hito Hito no Mi, Model: Nika, has never reached Roger’s hands.
Hito Hito no Mi, Model: Nika and Its Users in One Piece

There are two known users of the Hito Hito no Mi, Model: Nika. The first user appears in the Void Century, Joy Boy. This has been confirmed for a long time in the story, and it is mentioned that this infamous fruit has not been awakened for 800 years. This means Joy Boy must have awakened this devil fruit before Luffy, and he used its power to fight against 20 kings, even though he ultimately lost in that war.
Joy Boy died during the battle against the World Government, so his devil fruit was reincarnated. After Joy Boy’s death, the World Government has made numerous efforts to acquire this fruit.
The Celestial Dragons have tried to obtain the Nika fruit multiple times, and at the same time, it seems Cipher Pol has also gotten close to acquiring it, only to fail miserably due to Shanks. The Celestial Dragons clearly acknowledged that the Nika fruit has a special nature.
Indeed, a devil fruit can be recognized by anyone. This is particularly true for Zoan-type devil fruits, as they have a unique will. This is why Zoan fruits can only be awakened by the user they are meant for, or if a user fails, they may never realize their potential.
The Hito Hito no Mi, Model: Nika eventually found its way to Luffy and was awakened by him. During the Wano Country arc, Luffy finally awakened the infamous fruit, reaching new heights.
Why Didn’t the Nika Fruit Reach Roger? The Parallels Between Luffy and Roger in One Piece.

Luffy and Roger are characters who are very much alike; they share a cheerful disposition and are both beloved figures with strong convictions, yet they regard their own paths with great seriousness.
In essence, both have a similar core, and they share a dream. When Roger fought against the Marine Admirals, he revealed his own dream, which Luffy also spoke about while with Sabo and Ace. Shanks even mentioned to Rayleigh that Luffy has expressed sentiments similar to those Roger had on his journey. This is why Roger is often seen as the perfect candidate for the Hito Hito no Mi, Model: Nika.
Roger also bears a striking resemblance to Joy Boy, and it is clear that this character would have been the perfect user of the Nika fruit. However, Zoan-type fruits can only connect with the intended users, which is why Roger did not possess the Hito Hito no Mi, Model: Nika.
The reason for this is quite straightforward. The devil fruit has a spirit within it, and this is particularly true for Zoan types. They can sense their destined users, which is why they can only connect with individuals who are meant to wield them. The reason Roger is not considered a suitable user is rather simple.
Firstly, Roger fell ill and would not live long. When he became the Pirate King, he only had about one year left. No devil fruit can connect with someone who is on the verge of death. Yet, more importantly, Princess Shirahoshi was not yet born. It’s essential to remember that two kings must be born at the same time for the prophecy to hold true. When Roger reached Raftel, it was clearly stated that Princess Shirahoshi would be born in 10 years and would need another 16 years to mature. This means Roger was born 26 years too early.

This is precisely why Roger was rejected by the Nika fruit, despite his desire to become a complete Nika. It is clear that destiny always unfolds in mysterious ways, and Luffy is the chosen one destined to fulfill the ancient prophecy of the World Government.
Now that Luffy has awakened his devil fruit, it is only a matter of time before he uncovers the truth about the world and declares war against the World Government, bringing chaos to the throne.
While Roger could not fulfill this destiny, he was the one who set the stage for everything. Without him, the will of D could never be realized, and he has perfectly completed his role.