She is smarter than most Ravenclaws, but she is more brave than she is smart.

She prefers Gryffindor's values and even chose Gryffindor over Ravenclaw. and while she is very clever, she's more so in a book smart way, and doesn't have as much of the open mindedness/tendency to think outside the box that Ravenclaw covets.

If anybody is curious on why Hermione was not a Ravenclaw, I suggest you check out these websites:

https://fantasytopics.com/why-wasnt-hermione-granger-in-ravenclaw/

https://www.getsurrey.co.uk/whats-on/film-news/harry-potter-hermione-granger-definitely-23406560

https://www.quotev.com/story/12867910/Ravenclaw-Group-2/19

https://www.izzysbuzz.com/2020/12/22/5-reasons-why-hermione-granger-wasnt-sorted-into-ravenclaw/

https://wegotthiscovered.com/movies/why-wasnt-hermione-sorted-into-ravenclaw/

https://gamerant.com/harry-potter-hermione-ravenclaw/

I think Hermione wasn't a Ravenclaw bc she lacked their creativity and was really brave.