what did this book series get right in terms of worldbuilding/storytelling, even if it's not perfect?

im trying to understand how this book series appealed so much to me when i was a kid and got a special place in my heart. when i was 11 i was waiting for my hogwarts letter and i was so sad that it would never come 😂😂😂 for some reason i was convinced that the wizarding world was actually be real and i could secretly be a witch and i will go to hogwarts! im in my mid 20's now and wondering how her story managed to leave an impression in me years later