That sounds a little bit like the Lazarus Project, a BBC TV Show.

!A group of time travellers realised they could reset back to 1st of July at any point up to 1st July of the next year, because Earth passes through the trail of a quantum singularity at that point every year. They use this to try and save the planet when needed, only allowing the year to proceed if the conditions are as they want. An example used in the first episode is a new MRSA pandemic that keeps killing millions, they reset the year repeatedly until they have developed a vaccine so the pandemic only kills a few thousand.!<

!Except there are other time travellers who are trying to cause their own agendas to succeed or fail before resetting, or trying to prevent resets etc so that their branch of the year can continue!<

Not just the school aspect.

The idea of a young person who is mistreated in their day to day life escaping to a fanciful world where the normal rules don’t apply and they are accepted and loved by their peers. A world they enjoy and like, that sounds like a place they could belong.

Kids and even Adults want that, they want to put themselves into that character, they want to be that character. Look at the grown adults you see wearing “Still waiting for my letter from Hogwarts” t-shirts.

That is the appeal of Harry Potter. It’s escapism from real or imagined hardships in the reader’s day to day life into a world they WANT to be part of.

My wife suffered horrendous abuse growing up and Harry Potter was one of her few escapes, she wrote to J.K. Rowling to thank her for her means of escaping from the abuse, albeit mentally (although for various well documented reasons she now feels a bit differently about Rowling)