One possible reason could be that he is framed for a crime he didn't commit. Maybe someone with a vendetta against him planted false evidence to make it seem like he attacked a village or something similar.
In some fanfictions, Naruto might be imprisoned because the village elders fear his growing power. They think that by locking him up, they can control him and prevent him from becoming a threat, even though Naruto has always been loyal to the village.
Another reason could be related to a new and powerful enemy. This enemy might have some influence over the village's decision - making process and managed to get Naruto imprisoned as part of their plan to weaken the village's defenses, since Naruto is one of the strongest shinobi in the village.
Perhaps in the fanfiction, Naruto is tired because he is constantly traveling. He might be on a long - distance mission to gather information or allies, and the journey itself is exhausting. He could also be tired due to a lack of proper rest. Fanfiction writers might depict him as being so dedicated to his tasks that he neglects to take breaks, leading to fatigue. Or it could be that he is using too much of his chakra in experimental or new jutsu that he is trying to master in the fan - made stories, which leaves him drained.
One possible reason could be a conspiracy within the village. Maybe some powerful and corrupt individuals in the Hidden Leaf want to get rid of Naruto for their own gains. They might frame him for a serious crime like treason or murder to eliminate his influence as a hero. Another reason could be a misunderstanding. For example, Naruto might be in the wrong place at the wrong time and there are false witnesses who claim he committed a crime he didn't. Or perhaps an enemy from outside the village has managed to create a false scenario that makes it look like Naruto is guilty in order to cause chaos within the Leaf Village.
In some cases, the fanfiction might be a crossover with another universe where the idea of a ninja doesn't fit. So, to make Naruto fit into this new universe, the writer has to take away his ninja identity. This allows for new and interesting interactions between Naruto and characters from the other universe.
It could also be a way to show character development in reverse. In the original Naruto, he grows from an outcast to a respected ninja through hard work. In fanfiction, making him lazy could be a 'what - if' exploration of what would happen if he lost that drive. Maybe he faces some setbacks that make him question his purpose and become lazy as a result.
Perhaps it's because in the main Naruto storyline, Hinata has so many unspoken feelings for Naruto. Fanfiction gives her a platform to express those feelings more openly and in various scenarios that she may not get in the official story.
One possible reason could be his past experiences. Maybe he had some bad encounters when he was younger that made him self - conscious.
One possible reason could be a false accusation. Maybe someone spread a rumor that Naruto was involved in a heinous act, and without proper investigation, everyone turned against him.
It could be due to some sort of trauma. Maybe he witnessed something really bad that made him retreat into himself and become quiet. For example, if he saw someone he cared about get hurt badly, it could have silenced him as a form of self - protection.
One reason could be his power. His connection to the Nine - Tails makes him extremely powerful. In fanfiction, some in Konoha might fear this power and thus hate him. Another reason could be jealousy. Naruto becomes very popular and respected in the original story. But in fanfiction, some characters might be jealous of his achievements and turn that into hatred.
There are several potential reasons. It could be a result of a psychological experiment gone wrong. Some fanfictions like to play with the idea of Naruto being a test subject, and this could lead to his emotions being numbed. Another aspect could be related to his role as a leader. In some fanfictions, to be a strong and effective leader, he might believe he has to hide his emotions. Additionally, it could be a reaction to the expectations of others. If everyone expects him to be a fearless hero all the time, he might start to suppress his true emotions to meet those expectations.