I like the cybermen as a concept but it does kinda feel odd to me that there hasn't been a human farm story?

Where in the cybermen instead of conquering or mass force converting humans so that there is no more resistance.

Recognize they need a steady supply of people to convert that don't fight back.

One that isn't an origin story but where in the cybermen already won. where there is all but a select group of people akin to a zoo /farm merely used for breeding.

Maybe the cybermen make it extremely comfortable, the humans just view the cybermen as help/servants. Spoiled in what's basically an Eden to then ultimately be converted and denied living.

There's a lot of ways to go about it. Cybermen give these humans an Eden, treat them as pets, or worse treat them as livestock where there is no life. Just feed and grow until given the mercy of an upgrade cause the life they lived was never worth living.