It changes the dynamic. In the original, they meet at Hogwarts. But in fanfictions with this concept, they grow up together. So they have a deeper emotional connection from the start. For example, they might be more in sync when facing challenges at Hogwarts.
The 'Harry is raised with Hermione' idea often changes the relationships with other characters too. Since they are raised together, they might be seen as a unit by others. This can lead to different reactions from Ron, for instance. Maybe he feels a bit left out at first. Also, their combined knowledge and skills, which are developed during their upbringing together, can make them more formidable in the wizarding world. They might solve problems faster and in more creative ways. They could also have a different reputation among the students and teachers at Hogwarts compared to the original story.
In fanfictions with this concept, the way they approach magic can be very different. Growing up together, they would have shared their magical experiences from a young age. Harry might have been more academically inclined because of Hermione's influence. And Hermione might have been more adventurous due to Harry's presence. Their combined influence on each other can change how they interact with the magical world around them. They could start exploring magic outside of Hogwarts earlier, or they might have a different attitude towards house rivalries. This all creates a new and exciting version of the Harry Potter story.
If you want the clearest chapter reference, go to Chapter 63. Early on, During those seven days, he thought he had completely escaped from that...; later, the chapter leans on But now it seemed he hadn't..
Look to Chapter 49 for the clearest answer. It begins with My phone!!!" Jiang Yan's roar echoed continuously through the mountains in..., keeps building through Watching helplessly as his latest-model phone was taken away by a..., and lands on Thinking this, Jiang Yan marched forward, pulled Jiang.
If you want the clearest chapter reference, go to Chapter 74. Early on, Having seen Jiang Li's ID before, he knew that this person named Shiguang...; later, the chapter leans on And he only knew the answer to that one question..
Chapter 81 is the strongest chapter-level answer because it starts from Qi Tianyu, who chose curry beef rice, received a piece of curry and a... and follows through on The summer on the Southwest Plateau is no joke; the sun at three o'clock....
Chapter 22 is the strongest chapter-level answer because it starts from Hearing this, Su Yinwan looked at Shang Shaojing with a face full of... and follows through on Jiang Li's righteousness temporarily shut Jiang Yan up, but after a few....
The best chapter pointer here is Chapter 74, "Ordinary People". It opens with Having seen Jiang Li's ID before, he knew that this person named Shiguang... and closes on The man's phoenix eyes narrowed slightly, he looked at the girl sitting....
The best chapter pointer here is Chapter 45, "Give a Sweet Date and Then a Slap". It opens with Helplessly, Jiang Yan had no choice but to step on the accelerator. and closes on The guests have to go through so many troubles on the way, while these....
Chapter 98 is the strongest chapter-level answer because it starts from Jiang Li listened to the end and didn't have much of a reaction, only... and follows through on That's why she's not scared.]] Everyone held their breath, clearly, the....
Look to Chapter 82 for the clearest answer. It begins with Jiang Li gave her a fleeting glance., keeps building through When did we ever make a private deal?" "Just now!" Wen Jiaojiao defended..., and lands on And so, aside from Wen Jiaojiao, the remaining five set off, each....
The best chapter pointer here is Chapter 60, "The Human Oil King". It opens with What's with Jiang Yan, treating his own sister Jiang Li like this?" "He... and closes on And in traditional characters?" "What else?.