I mean this has been a thing for years
The Hunger Games series
Harry Potter (actually quite tame until the back half of the series, and much more tame than Wings of Fire)
Percy Jackson (more tame than Wings of Fire though)
are just a few violent book series advertised with a target audience of around that age group. I’d wager The Hunger Games is targeted towards those closer to fourteen and fifteen year olds while Harry Potter and Percy Jackson are books people think are cool in 4th grade from my experience. All of which people find perfectly acceptable to read later.