Apart from those highly concentrated cities, outside of the wilderness, people have always lived.
But there's a reason why people prefer to suffer and die in cities rather than venture into the wilderness.
The wilderness never became a primary human habitation because it's inherently unsuitable for people to live in. High levels of radiation and the harsh environment and weather have transformed the wilderness into a land of death.
Those struggling in the wilderness couldn't even be called human, they were more like animals that couldn't even speak.
Not to mention due to the impact of radiation during pregnancy, the people who survived in the wilderness almost all had various physical deformities.
They fed on the equally deformed animals, as well as city garbage, occupying the same ecological niche as cockroaches.
Wild people have always been somewhat of an urban legend in Metropolis, even serving as a form of spiritual sustenance.
