In fiction, tropes are like garlic and onions. They add richness and flavor to a dish. Something is missing without them. Too many though, and the food starts to taste a little sweaty, the way moldy old gym clothes smell. They overpower what could be a good dinner.
YA novels walk that line between children's and adult books and it's a hard balance to perfect.
Purple Prose your way into this genre, it's so much fun.