This story is simple and straightforward, and the absolute sincerity is what makes the ending so impactful.
This is the only short story that has ever made me cry. And by that, I mean it's fantastic. I'm pretty stoic as sentimentality goes, with a low tolerance for sappiness and a super-sensitive gag reflex for saccharine. Slow-clap moments make me want to gouge someone's eyes out (preferably the author of said moment). So when I say this story made me cry, I mean that it struck me emotionally in a way free from pandering or pretension.