One thing that I always wanted to talk about Wizarding World (particularly, Harry Potter universe) is that the lack of diverse (not race) in terms of characterization and the world itself tbh.
JK Rowling has build this immersive world and myth that could have rivaling Game of Thrones and yet...it seems so little and very limiting.
We barely seen the world outside Hogwarts.
And Rowling writes about the 4 founding houses in Hogwarts and yet she only focused on Gryffindor and to lesser extent, Slytherin. We barely knows about Huttlepuff and Ravenclaw and what type of wizards coming from their houses.
Having almost all prominent characters be from Gryffindor was very boring, to me. Lack of imaginative, I'd say.
If I were Rowling, I'd make each of 4 respective houses had their own main and prominent character. Instead of making all of them coming from Gryffindor, I'd make all of them coming from different houses. Let Harry and Hermione still be from Gryffindor, but the rest of characters (be that Ron, Neville, Sheamus, George, Fred, etc) coming from the other 3 houses. Be that from Ravenclaw, Huttlepuff or even Slytherin (---> don't make all of them a one note sinister and villanious characters, for God's sake!). That way, not only it would have a very diverse characterization between all of the characters but also it would enrich the world and the myth itself.
And explore the other schools around the world (the best part of Goblet of Fire that it doesnt revolve just around Hogwarts...but the other part of the wizarding world). Why limiting the story to just Hogwarts?