There are exceptions:
Princess Bride
It is worth reading the so-called abridger's notes to the The Princess Bride, precisely because they emphasize the theme of non-endings. In the book, the son (grandson) is even more devastated when Westley dies. He refuses to go on reading the book, only agreeing to hear the rest several days later.
Generally speaking, I argue against stories with no endings or closures, but in The Princess Bride the (grand)son is not only hearing a story and bonding with a parent, he is also undergoing a rite of passage.
The original novel ends in this way:
However, this was before Indigo's wound reopened, and Westley relapsed again, and Fezzik took the wrong turn, and Buttercup's horse threw a shoe. And the night behind them was filled with the crescendoing sound of pursuit.The "abridger" acknowledges that this is a "Lady or the Tiger" ending. He wraps-up:
[I]n my opinion . . . [Westley and Buttercup] squabbled a lot, and Buttercup lost her looks eventually, and one day Fezzik lost a fight and some hotshot kid whipped Indigo with a sword and Westley was never able to really sleep sound because of Humperdinck maybe being on the trail. I'm not trying to make this a downer, understand. I mean, I really do think that love is the best thing in the world, except for cough drops. But I also have to say, for the umpty-umpth time, that life isn't fair. It's just fairer than death, that's all.So the movie ending with the kiss (no fastforward to Buttercup and Westley and their life post-movie) followed by the grandfather and grandson's farewell is perfectly appropriate--because those are the fair moments that an unfair life is comprised of. (The current edition of the book has more notes and a short story.)
Joe v. the Volcano
The movie is a romance--and not. It is about Tom Hank's Joe meeting his Meg Ryan(s).
However, the climax of the movie occurs when Joe stumbles to his knees on the ocean and proclaims through cracked lips, "O God whose name I do not know, thank you for my life."
At the end, they float off "away from the things of man." Like in The Princess Bride, it is more than likely that they will undergo a lifetime of adventures and upheavals. Good for them! That life is theirs. We don't need to be there to see it.