I'm perfectly fine in most contexts when the hero is not the one to deliver the death blow, who actually needs help to defeat the villain and is gracious about how he can't do it alone. It does depend very much on the context, I agree. The hero who goes off alone to take down the villain and then gets caught and gloated over in the super-secret villain lair is such a trope that it pretty much no longer pings me at all. But when they make their share of mistakes, there is such a thing as piling it on too deep for me to bear. I didn't see that so much in this film! But, like you, I still want my hero to be heroic in the end, whether that's dealing a death blow, choosing not to deal a death blow, or being gracious when someone lends them a hand in the defeating.