It’s a truth universally acknowledged that sometimes happy endings in movies & TV shows are complete bonkers. Everything will go wrong during the course of the show, villages will burn, people will plunder but somehow it wraps up all happily in a neat bow. AND WE LOVE IT. I know for a fact that I would not love Stardust or The Princess Bride as much if they had even close to a realistic ending. Futurama I could deal with but that show oddly makes me cry a lot for being a cartoon.
No one really wants to see the guy not get the girl or the villain win and while it would be insanely fun to watch it would be deflating in the end. Human nature puts us in the shoes of whoever we feel to be right in the situation and we always want to win.