It could also be that in this fanfiction, the story is set in an alternate universe where there are different power dynamics. Maybe there are other more suitable or available mentors for Naruto in this universe, and Jiraiya's skills or expertise are not as relevant or needed as in the original Naruto storyline.
Perhaps Jiraiya has some personal issues or inner conflicts. He might be dealing with his own past traumas or demons that prevent him from taking on the role of Naruto's trainer. For example, he could be haunted by the failures in his previous relationships or battles, and he feels unfit to train Naruto until he sorts out his own problems.
One possible reason could be that in this fanfiction, Jiraiya might be preoccupied with other important matters. Maybe he has a secret mission that demands his full attention and he simply doesn't have the time to train Naruto. Another reason could be that there is some sort of conflict or misunderstanding between them that prevents Jiraiya from taking Naruto under his wing. For example, Naruto might have unknowingly offended Jiraiya in some way, or there could be a prophecy or external force that is keeping them apart for the time being.
Another reason could be that Jiraiya has some doubts about Naruto's readiness or potential. He might think that Naruto is not yet at the level where he can fully benefit from Jiraiya's training. For example, Naruto may lack some basic skills or knowledge that Jiraiya believes are necessary prerequisites for his more advanced training.
One possible reason could be that Naruto feels he has learned all he can from Jiraiya at that point. Maybe he has reached a level in his training where he believes he needs new experiences and challenges that Jiraiya can no longer provide.
One possible reason could be that Naruto feels he has learned all he can from Jiraiya at that point. Maybe he wants to explore his own path independently and test his skills without Jiraiya's constant guidance.
One possible reason could be that Naruto might feel Jiraiya is being too overbearing in his training methods. In some fanfictions, Jiraiya might push Naruto too hard without considering his emotional state, leading to Naruto snapping.
One possible reason could be that in the fanfic, Jiraiya might have made a decision that Naruto strongly disagreed with, like leaving him alone at a crucial time for a long mission. This could make Naruto feel abandoned and thus start to hate him.
One possible reason could be jealousy. Maybe in the fanfiction, Jiraiya gives more attention to another character, and Naruto, being young and impulsive, starts to hate him for it.
One possible reason could be that the writer lost inspiration. Jiraiya has a complex character in the Naruto series, and it might be difficult to keep coming up with new and interesting plotlines for him in fanfiction. Another reason could be that the writer got involved in other projects or fandoms and simply didn't have the time to continue with the Naruto fanfiction centered around Jiraiya.
Naruto might develop different skills. Without Jiraiya's training, he could focus more on self - taught techniques or learn from other characters. For example, he might learn more about the Uzumaki clan's unique abilities from someone else in the village.
Well, in the original story, Jiraiya played a big role in Naruto's emotional growth too. If he doesn't train Naruto in the fanfiction, Naruto might lack the father - figure like guidance that Jiraiya provided. This could lead to Naruto making different decisions in life, both in terms of his relationships and his ninja career. For example, he might not have the same understanding of the ninja world's politics and power struggles, which could put him at a disadvantage. Also, his connection to the Sage Mode might be completely different or non - existent, which would change how he fares in battles against powerful enemies.