Organize fanfiction contests. This can draw attention to the creativity within the fanfiction community. Winners can get some recognition, which would help to boost the overall perception of Harry Potter fanfiction.
One consequence could be an imbalance in the world's population. There might be too many people for the existing resources, leading to shortages of food, water, and living space.
It could be that his new 'godlike' power has isolated him. People might be either in awe or afraid of him, and he may feel that he can't be close to others as before. So he acts coldly as a defense mechanism.
Snape underestimates Hermione in fanfiction perhaps due to his own biases. He is a Slytherin and she is a Gryffindor, and he has a rather harsh view of Gryffindors in general. This underestimation can create interesting plot twists. Hermione, being the brilliant witch she is, uses his underestimation to her advantage, like when she outsmarts him in potions or magic theory, which makes for engaging reading.
Well, in some fanfictions, Naruto might use some super powerful jutsu that he either discovers or creates. Maybe it's a new form of the Rasengan combined with some sealing techniques. It could also be that he taps into some ancient power or makes a deal with some sort of god - like entity within the Naruto universe.
Maybe he got some kind of curse. In the Naruto universe, there are all sorts of dark magic and curses. If he was cursed, it could make him withdrawn and cause him to ignore everyone.
One possible reason could be a powerful genjutsu cast over the village. Maybe an enemy ninja with strong illusionary powers managed to make everyone forget Naruto. It could also be due to some sort of curse. For example, a dark curse was placed on Naruto that made people's memories of him fade away gradually.
One possible reason could be that Naruto has seen or experienced something that makes him distrust or fear those around him. Maybe he has discovered a dark secret about the village or his friends that has shaken his beliefs.
It could also be that Naruto has had some sort of revelation about himself or the ninja world. He might have realized that the relationships he has been in were holding him back in some way. Maybe he wants to focus on self - improvement and growth, and he believes that being alone is the best way to do that. He could be trying to find his true self without the influence of others.
Maybe in that fanfiction, Naruto's over - eagerness to be recognized could be misconstrued. His loud and boisterous nature might annoy people. For example, if he constantly interrupted others or pushed his ideas too hard without considering others' feelings, it could lead to dislike.