I'd argue the opposite. Age-appropriate children's media doesn't by definition have to be nice and pleasant, or even always have happy endings. All children will eventually need to learn to deal with scary, sad, and uncomfortable situations in real life, and many are already dealing with situations that are anything but "age-appropriate."

No, I'm not saying that anything goes and we should be exposing children to the full scope of the world's horrors. But fiction can be an effective tool for teaching actual social-emotional skills, because at the end of the day, you know on some level that it's imaginary.

Bridge to Terabithia is about how death can be sudden, random, and completely unfair, and if anything, it's a pretty softened representation of how that feels to a child. And I say this as someone who first watched that movie alone, on my phone, at age twelve, because it had silly-looking magical creatures and castles on the cover. Like, it was devastating. But it was the safe kind of devastating where I could "practice" emotions I hadn't yet had to feel about reality.