Beyond its crux, the flippancy with which The Ones Who Walk Away From Omelas' narrator invents the city is the most distinctive aspect of the story to me. There's a reading where the suffering child is optional - only necessary if you can't buy the first two and a half pages - because the narrator is only negotiating with our suspension of disbelief, not telling us about a place that Really Exists.

In that way, if you can imagine or accept that this miraculous little city could exist without need of suffering, without any catch, then the child doesn't exist. It's only if you read on (because of zero-sum thinking or narrative necessity or the fact that it's a story and the point is to read on past rhetorical invitations not to) that the child is placed in the cellar.

Conditional on the child existing, within that world, there are those that walk away, some of whom presumably envision a better, more just city free of sacrificial eight-year-olds. You like to imagine you'd be one of these people.

But they're only doing that because you, the recipient of this parable, prefer to accept that arrangement than the one where there are no strings attached.

It's a metafictional knot. How this reading influences my interpretation of what the story is saying we ought to do, I have no idea. I'm surely missing context on Le Guin's apparent exasperation with whoever her contemporaries were that considered Good Art to explore suffering and Bad Art to depict flourishing ("treason of the artist", "bland utopians", etc) but that seems pretty important here. Of course, historically, one innocent child suffering for all our salvation has been considered a pretty good deal.

I guess it changes one of the stories takeaways from "refuse utilitarian bargains" to something more like "repair the imaginative failure that made the bargain seem necessary."