They're missing reality.
Here's what I mean by this. YA fiction & fantasy fall into one of two categories.
Category 1: Adventurous hero or heroine battle demons, angels or other supernatural beings in order to save the world, right a wrong, and on the way, fall in love with one another. Their epic love story is usually star-crossed, and both hero and heroine and friends feel intensely during their battle.
Category 2: Main protagonist has to deal with life in a really crummy situation- whether it's them or their friend who is dealing with mental health issues, drugs, an eating disorder, cancer and so on. They are a wry, interesting, irascible or spiritual character who pulls the reader in.
Here's the problem. These two categories don't cross over in a meaningful way. Let me offer an example.
An example of a Category 1 book is Cassandra Clare's The Mortal Instruments trilogy. Clary, Jace and Simon, alongside Isabelle, Alec, Magnus and others battle all sorts of difficult creatures and situations, but all of their feelings and issues revolve around love. Yes, Jace is a little messed up because of his father (who raised him to think that love is a weakness, and that loving would break him), but it's nothing a little love from Clary can't fix. These characters don't have to deal with their issues or emotions in a real way. They don't have real-life reactions to the situations they face (Post-Traumatic Stress Disorder, depression, other mental health issues) and they don't have to deal with them in real ways (therapy, for instance).
An example of a Category 2 book is The Fault in Our Stars by John Green. This moving and hilarious book makes cancer funny. It explores the lives of two people battling cancer, one of whom makes it and one of whom doesn't. The friendships read as real, the issues (whether dealing with the cancer, trying to avoid dealing with the cancer, or wanting to find love) read as real.
What troubles me is that the real life issues that are faced in books like Speak, The Fault in Our Stars, Hush and so on are not addressed in fantasy novels. Now, I can understand why that is. Most fantasy writers like to make completely separate worlds where the issues are fully external (or internal at times, but overcome by a little love). But I think this actually weakens the fantasy world. In a true fantasy world, people love, grieve, and are impacted by the events that occur. People are not just cold-blooded killers who never have to deal with PTSD or deal with phantom limb pain or who have flashbacks after being raped. Making reality converge with fantasy would actually, in my opinion, make the fantasy book stronger.
An author who does this really well is Madeline L'Engle. Her book A Wrinkle in Time is a masterpiece because she weaves science fiction together with a real life heroine who is insecure, does not feel pretty and ends up having a real, complicated relationship with Calvin O' Keefe (not just one brimming with sexual tension where the two of them must end up in bed together and that solves all their problems). Susan Cooper also does this well in her series The Dark is Rising. But both of these authors have been largely replaced by contemporary, and to the large part, shoddy, fantasy writing.
Even Harry Potter, which everyone read and was dazzled by due to its 'realness'- an actual ministry, laws, shady newspaper reporters, a seemingly unloved child- never allowed any of its characters to struggle with an actual diagnosed condition. Harry didn't suffer from depression. He didn't have to see a therapist. He was in the nurse's wing or the hospital pretty frequently, but problems with his mental state? Never. Even after everything he had gone through, all the loss he had suffered. Even after living his whole life with a person whose mission it was to kill him. Tip top mental shape.
If fantasy is, as many authors espouse, their way to enable students and children to interact with the world and find solutions for the monsters that threaten, it isn't enough to equip characters with otherworldly talents, traits or supernatural abilities. These characters should be real in every way, including the toll their actions take on them, including their mental health status and the actions they need to take to be healthy. If YA fantasy wants to aid the battle to help young people feel normal, it needs to focus on more than just gay characters or bullying. It needs to focus on making young people feel like it is okay to seek help when they struggle with their mental states. Otherwise, fantasy just joins the ranks of role models for people that says 'If they could get through all of this and be perfectly fine, no sweat, no therapy, no struggling, just a soulmate who loved them back to health, then I should be able to do it, too.' That message is unhelpful and even dangerous.
So YA Fantasy authors, be brave. Take the next step. Start making your characters real.
Our kids will thank you for it.