Another reason could be political. After the war, the power dynamics in the village might have changed. There could be new leaders or groups who saw Naruto as a threat to their authority. They might have plotted to make him look bad and turn the villagers against him, causing him to feel betrayed by the very people he fought for.
Jealousy could also play a part. Naruto becomes very powerful over time. Some of his peers or even superiors in the village might be jealous of his growth and popularity. They could spread lies and manipulate others into believing that Naruto is a threat. This would gradually turn the whole village against him. For example, a less - known ninja who feels overshadowed by Naruto's achievements might start the ball rolling on the betrayal.
One possible reason could be fear. Naruto is extremely powerful, and some in Konoha might fear that he could one day lose control of his power. Another reason could be political intrigue. There may be certain factions within Konoha that see Naruto as a threat to their power and influence. Also, jealousy might play a part. Naruto has achieved so much and has the love of many, and some might be jealous and thus plot against him.
He would probably be heartbroken at first. Naruto has always been someone who values his bonds with others. Being betrayed by the village he loves would be a huge blow. He might isolate himself for a while, trying to figure out what went wrong.
One possible reason could be that she was forced to betray him. Maybe an enemy got to her family and threatened her to turn on Naruto. For example, in the Naruto universe, there are many powerful villains who would stoop to such tactics.
One possible reason could be a misunderstanding. Maybe Naruto is forced into a situation where he has to take actions that seem like a betrayal to the Uchiha. For example, if there are political forces at play that make Naruto choose between the safety of the village as a whole and the specific interests of the Uchiha clan. Naruto, being a firm believer in the village's unity, might make a choice that the Uchiha perceive as betrayal.
It could also be due to outside influence. An enemy might deceive Naruto's team into believing that Naruto has turned against them. The enemy could plant false evidence or use mind - control techniques on the team members, causing them to turn on Naruto without realizing the truth.
One possible reason could be jealousy. Maybe Sasuke in the fanfiction becomes jealous of Naruto's growing power and decides to betray him for his own gain. Another reason might be a misunderstanding. For example, if Naruto is wrongly accused of something terrible, and the rest of Team 7 believes it without giving him a chance to explain, they could turn on him. It could also be due to outside influence. Perhaps an enemy manipulates Team 7 into believing that Naruto is a threat to them, leading to their betrayal.
Another reason might be related to a difference in ideology. Kakashi might have a different view on how to achieve peace or protect the village compared to Naruto. This divergence could lead to actions that Naruto interprets as betrayal. For example, Kakashi might believe in a more conservative approach that involves sacrificing some of Naruto's ideals in order to maintain the stability of the village.
In such a fanfiction, one possible reason could be a misunderstanding. Maybe Sarutobi is misled by false information about Naruto. For example, if some villains manage to plant evidence that makes Naruto seem like a traitor. Another reason could be for the so - called 'greater good'. Sarutobi might think that sacrificing Naruto would save the village from a greater threat. However, this would be a very controversial decision as Naruto is the main character and is supposed to be a hero in the original story.
In these fanfictions, it might be related to the secrets Naruto holds. For example, if he discovers something about Konoha's dark past that certain people don't want exposed. They would then try to get rid of him by making him look like a traitor. Also, there could be external forces influencing Konoha to turn against Naruto, like other villages spreading false rumors.