I am sick unto death of people responding to criticism of a needlessly dark, pointlessly depressing ending with “Well, in real life, sometimes you don’t get happy endings. That means it’s good!”
No, it doesn’t.
I am not saying that every story needs to have a happy ending, because that would be stupid. Since time immemorial, there have been stories with sad endings. One of the greatest SF/F movies is The Thing, where the best case scenario is that the only two remaining characters die in a few hours, and the entire Earth doesn’t get swallowed up.
The difference is, in that movie the realism EARNS a sad ending. It doesn’t come out of nowhere. The story whittles down the cast little by little, keeping them isolated and self-contained, highlighting the horrors they face, and making it clear that they’ll do whatever it takes to save the Earth. So it doesn’t feel out of place when the main characters are essentially condemned to death by their own actions, because that outcome naturally evolved from the stuff they had been doing and the place they had been.
Compare it to, say, the movie Justice League Dark: Apokalips War or the planned finale of the 2012 Teenage Mutant Ninja Turtles series (before Nickelodeon stepped in and declared it was another dimension or an alternate future or whatever). There was nothing to build up to those dark miserable outcomes. It’s the writing equivalent of “Rocks fall, everybody dies” — the people creating it simply decided to make everything go to hell so it could be crappy. They ultimately made everything that had come before MEANINGLESS for the sake of a dark, unhappy outcome, rather than writing a finale that actually feels satisfying for the audience and draws from what has come before.
Why? Do they think it’s “deep” if a story has a miserable ending, even if that ending isn’t earned and doesn’t naturally stem from anything? Do they think that happy endings “suck,” like some tiresome fourteen-year-old edgelord?
And as a final middle finger to the people who whine that “real life sometimes doesn’t have happy endings,” I ask you: why do you want the worst of reality reflected in fiction? Because when you introduce body-snatching alien parasites, mutant turtles and superheroes on the level of Superman, you have lost claim to “real life.” There are varying degrees of “reality” in any form of fiction, and sci-fi/fantasy is where it has the loosest control over the narrative.
Want to cure someone of cancer? There’s magic and alien technology for that! Want to leave your mundane job behind? That can happen! As long as it’s done with internal consistency and good writing, you can do all sorts of stuff that doesn’t happen in “real life.”
So why should “real life” have a stranglehold over the endings of sci-fi/fantasy TV/movie series/books? If your narrative conventions allow you to do all sorts of incredible unbelievable unrealistic things, why are you inexplicably determined to make “real life” the benchmark?
And considering that “real life” is incredibly sucky and there are no long-term happy endings because we all die, why the hell should our fiction reflect that? Why shouldn’t we have happy endings in fiction?
And again, I’m not saying every ending has to be puppies and rainbows. A good example of a satisfying finale would be Avengers: Endgame, which mixes the tragic with the triumphant. We lose characters we’ve come to love over the course of many years of movies, but it feels earned because their deaths MEAN something to the story. They weren’t killed off because “happy endings suck and we’re edgy,” and the overall feeling is that because they sacrificed their lives, the world has a chance to be a better place where the people they’ve saved can live on.
So a bittersweet or sad ending is not necessarily a bad ending, but it has to be based on something more artistically valid than “well, sometimes there aren’t happy endings in real life and the good guys don’t win!” That is an excuse, not a reason.
If you are giving your story an unhappy, depressing ending just to have it be unhappy and depressing, you are doing a disservice to your art, your characters and your audience. So don’t do it.