Ending a story should resolve an overarching plot. If you done that, even if it feels unsatisfying, know that you've done a good job at untying that knot. You done a good one.
End your characters instead then. Why should they live and your story die? It's not fair! You're the author the one who bleed for the story, those characters just get a life where success is guaranteed in the end? NO! Ruin them and let your story live on. Replace them with the next generation of characters who will rise to glory over their dead bodies. Make your story a trilogy! Thrice. Then go quartet out of spite.
Then leave it open-ended?
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