Characters who have amazing abilities are just about the coolest thing ever. Especially if they are a unique ability that you get to see develop over the course of an extensive time period. The pay off is amazing and the fight against the bad guy feels well earned.
But often times in Young Adult, Fantasy, and Sci-Fi there is an element of protection for these characters. They'll suffer but only a little bit. They might have tragic backstories, but those stories aren't going to affect them 'too much.'
Too often these characters become OP (overpowered) and lose their human element to them.