Harry's life would change drastically. He'd probably be very lonely. Without his parents, he might not have access to proper education or resources. He could get involved with the wrong crowd just to have some sense of belonging. His magical abilities might develop in a different way, either being suppressed due to the trauma or becoming more wild and uncontrollable as he has no one to guide him properly.
His life could become very difficult. He might have to fend for himself at a very young age. Maybe he has to live on the streets, stealing food just to survive.
Naruto's view of the world can be quite different. Without his parents, he may feel like an outsider more strongly. This can lead to him having a more complex view of the ninja village. He might question some of the village's values and traditions. At the same time, he could also develop a greater sense of empathy for others who are alone or have lost their families. He may be more likely to reach out to those people and try to help them, which in turn can have a big impact on the overall plot of the fanfiction.
In some fanfics, they might abandon Harry because they are under a dark spell. This spell could make them lose their love for him and force them to leave. Another reason could be that they are blackmailed by some powerful dark forces. These forces may threaten their lives if they don't abandon Harry.
It might make him see them more as real people. Before, they were just an idea of parents, but the trunk could contain things that show their personalities, like their sense of humor or their interests.
Well, if Harry's parents were alive in the fanfiction, his life would be drastically different. He would grow up in a loving family environment, not having to endure the abuse from the Dursleys. He'd likely be more confident and less haunted by the past. His parents could teach him magic from a young age, and he might not have the same drive to prove himself as he does in the original story.
His diet changes. Instead of regular food, he now has a craving for blood. His sleeping patterns might also be different. He could become more nocturnal.
In fanfiction, his alive parents could abandon Harry due to a prophecy. They might have been told that Harry was destined for great evil or something terrible was going to happen because of him. So, in a misguided attempt to prevent this, they abandoned him. Or perhaps they were under some kind of dark magic influence that made them believe that Harry was a danger to them or the wizarding world, even though it was all false.
Naruto would probably become more independent. Without his parents' support, he has to rely on himself. He might start to train harder to prove himself to everyone.
These fanfictions usually change the story of Harry's parents in multiple ways. Firstly, their safety. They might not have had to go into hiding if the wrong boy was believed to be the chosen one. Their relationship with the wizarding community would be altered too. They might not have had the same level of support or the same amount of enemies. Also, the way they are remembered would be different. Their story might not be one of great sacrifice but rather of a normal wizarding family caught up in a misidentified prophecy.
Well, in such a fanfic, Naruto's character would change a great deal. He might become more self - reliant at a very early age. Since he doesn't have parental figures to rely on, he'd have to figure things out on his own. This could make him tougher, but also more bitter. He may not have that same optimistic outlook that he has in the original story because the neglect could have made him cynical about the world and people around him.
Financially, if his parents were the main source of income, he would have to find a way to support himself. This could lead to him taking on odd jobs or starting an apprenticeship. Emotionally, he may carry the pain of their loss throughout the story, but it could also fuel his determination to succeed or make a difference in the world.