In some fanfictions, Naruto might feel left out because he has a unique background. He was an outcast in the village at first. Maybe the other characters in the fanfic are forming groups or having relationships that don't include him. For example, if there are new teams being formed and he's not part of them, it could make him feel left out.
Well, it could be due to his power level in the fanfiction. If the story focuses on other characters with different or more 'desirable' powers, Naruto might be sidelined. He's used to being in the spotlight in the original story, but in the fanfic, if the author decides to shift the focus, he could end up feeling left out. Also, if there are new social dynamics introduced, like a new clique of ninjas that he doesn't fit into, that would contribute to his feeling of being left out.
Naruto might feel left out in fanfiction for several reasons. One possibility is that the plot of the fanfiction revolves around a different set of characters' personal stories, leaving Naruto on the periphery. For instance, if the fanfic is mainly about the Uchiha clan's internal affairs and their relationships, Naruto, being an outsider to that family drama, may be left out. Another reason could be changes in the characterizations. If the other characters in the fanfic are made more exclusive or less friendly towards Naruto, it would definitely make him feel left out.
One reason might be related to his sense of responsibility. Naruto feels a huge obligation to protect the village and his friends. In fanfiction, when things go wrong or he fails in some small way, he could start to feel undeserving of all the good things in his life. He might think that if he can't fulfill his duties perfectly, he doesn't deserve the love, the power, or the status he has. Also, his own high standards for himself, which he has developed over the years of trying to prove himself, can make him feel unworthy when he falls short in any way.
Maybe it's because of the deep bond they share and the sense of loss Kakashi feels when Naruto leaves.
In some fanfics, Naruto might feel unwanted because the author wants to explore a darker or more angsty side of his character. They may show him being excluded by the villagers even more than in the original story, perhaps to create a different kind of character development arc where he has to overcome not only external enemies but also this sense of being an outcast within his own community.
Maybe Percy feels worthless because he constantly compares himself to others. In the fanfiction world, there could be characters who seem to have more power or popularity, making Percy feel inferior.
It could be that the writer wants to explore different character dynamics within Gryffindor without Harry overshadowing them. Maybe they want to focus on the other Gryffindor students' growth and relationships that are often in Harry's shadow in the original story.
Maybe it's because of something he did that had unexpected consequences.
One reason could be the epic nature of both. Naruto has a grand story of a young ninja's journey to become Hokage, facing powerful enemies and saving his village. Similarly, Final Fantasy often features heroes on a large - scale quest to save the world from various threats.
Naruto could try to reach out to the other characters. He's a very determined person, so he could make an effort to join in on their activities or conversations. For example, if they're having a training session, he could ask if he can participate.
You might feel left out because your childbirth story was very different and you don't relate to what they're saying. Or perhaps you haven't had the opportunity to fully engage in the conversation and express your thoughts.
Maybe it's because you haven't had the same experiences as them or haven't been through the exact same phases of pregnancy.