I'm not a proponent of the idea that happy, functional characters can't be interesting, far from it. But I am perfectly fine with terrible things happening to them for the entertainment of the audience. I don't think that fictional characters deserve anything, being fictional and all. The people who deserve things are the audience, not the characters.
The audience deserves characters who are well-rounded and complex, who aren't sterotypes. The audience deserves a cast of characters which reflects its own diversity. The audience deserves protagonists who have agency. The audience deserves storylines that aren't lazy.
If the audience gets all those things... then sometimes, fictional characters will still have terrible things happen to them. But it will seem a lot less meaningless and insulting when they do.
