If one innocent person is tortured so that everyone else can live and the world doesn't end, is that simultaneously unfair but also morally preferable over complete destruction of everything?
Basically the plot of this story. It poses the issue of how much we value society over the individual, and if that is good or not. Would you want to live in a world that depended on the the torture of a single person. You then could extrapolate that out to societies in the real world, US and chattel slavery. the west and the use of sweat shop labor for cheap products, the Emirates and their use of migrants as indentured servants. Even tipped wages for servers in the USA, the gig economy, and things like medical residencies could be considered a minor version of Omelas. As humans, we often tolerate the abuse or exploitation of others for our own benefit, or even just out of ignorance and inaction.
It always strikes me how few female sci-fi and fantasy writers I've read. I've tried amending that mistake over the last couple of years but it's not easy, especially when looking for books translated into more obscure languages.
Julian May has a great series in two parts, the Saga of Pliocene exiles and the Galactic Milieu trilogy. Amazing books, great story, very moving and thought provoking.