This only sort of relates (the earlier comment about natural resources being more important than human resources made me think of it)…
A friend of mine described a dream he had-- basically this was the story.
People were being born and grown as an organ harvest. While they were raised, they took care of all the important jobs and maintenance of the city, and when one of the elites needed a transplant or was sick, a worker would be sacrificed.
Yep, that’s it. Just thought that could maybe spur some ideas. Or just be interesting.