One possible reason could be jealousy. Maybe some of his former allies were envious of his fame and hero status. Another reason might be political manipulation. There could be those who wanted to use his downfall for their own gain in the post - war wizarding world.
Well, it could be that there were secrets about Harry that were revealed after the war. For example, if there were some things he did during the war that were considered morally grey in hindsight, like using certain dark spells in extreme situations. This could lead to some people feeling betrayed by him and turning against him. Also, power struggles are common. If Harry was seen as a threat to the established power structure in the wizarding world, they might plot to make it seem like he had betrayed them first so they could get rid of him.
In the post - war wizarding world, things were changing rapidly. Harry might have been betrayed because he was too idealistic. He could have proposed radical changes that some traditionalist wizards didn't like. They might have felt that he was going to disrupt their long - held way of life. Additionally, misinformation could play a big role. If false rumors were spread about Harry, like he was planning to take over the Ministry of Magic by force, people who didn't know the truth might believe it and see his actions as a betrayal, even if he had no such intentions.
Well, one reason could be jealousy. Maybe his friends envy his fame or special abilities. Another could be misinformation. If they are fed false information about Harry, they might turn against him. For example, if someone convinces them that Harry is secretly working for the enemy.
Well, it could be that Naruto's friends are influenced by a dark power. This power could twist their perception of Naruto, making them see him as a threat instead of a friend. Or perhaps there's a prophecy that Naruto is supposed to be the cause of some great disaster, and his friends, in an attempt to prevent it, decide to betray him. It's also possible that a new character enters the story and sows seeds of discord among them, leading to the betrayal.
One possible reason could be a misunderstanding. Maybe Artemis misinterprets Percy's actions as a threat to her or her hunters. For example, if Percy accidentally endangers one of the hunters while trying to save someone else, Artemis might see it as a betrayal of her trust in him to respect her followers.
Sometimes, it could be a matter of different loyalties. Naruto's friends might have family or other obligations that conflict with their loyalty to him. For instance, if their families are threatened by someone who demands they betray Naruto, they might feel compelled to do so out of a sense of protecting their loved ones.
In some fanfics, Ron could be influenced by dark magic or dark forces. Maybe he gets cursed, and as a result, his mind is twisted to turn against Harry. It could start with small acts of undermining Harry and escalate to a full - blown betrayal. This is an interesting concept as it shows how external forces can change a character's nature.
One possible reason could be a misunderstanding. Maybe Inuyasha misinterprets Kagome's actions or words. For example, if Kagome is trying to help a new character who seems to have a connection to the Shikon Jewel, Inuyasha might think she's being disloyal and thus betray her. Another reason could be some sort of dark influence. There could be an evil force that makes Inuyasha act out of character and turn against Kagome.
It could also be that Harry himself is so traumatized by the war that he isolates himself. He might push people away, thinking that he's a danger to them. As he withdraws, others might misinterpret it as him not wanting their company and gradually abandon him.
Well, in some fanfictions, it could be part of a much larger conspiracy within the Ministry of Magic. There could be a group within the ministry that has gone rogue and they see Harry as a symbol of resistance against their corrupt plans. So, they betray him to silence him and make an example out of him. They might also think that by getting rid of Harry, they can better control the wizarding population who often look up to Harry as a hero.
One possible reason could be that she is influenced by an enemy. Maybe the enemy has some sort of leverage over her or has brainwashed her into believing that Naruto is a threat. Another reason might be a misunderstanding. For example, she could misinterpret Naruto's actions as being unfaithful or harmful when in reality he has good intentions. It could also be due to her own insecurities. If she feels overshadowed by Naruto's popularity and power, she might betray him to assert her own identity.
One possible plotline could be that some of the former Death Eaters who were pardoned as part of the post - war reconciliation secretly plot against Harry. They might spread false rumors about him misusing his power or being a threat to the wizarding world again. Another could be that some of his own friends turn on him out of jealousy. Maybe they feel overshadowed by Harry's continued fame and hero status and start to believe the lies being spread about him.