The areas just outside Sprawls are technically livable, but a totally lawless warlord-run frontier where oxygen is at a premium, and anyone with the power to govern doesn't have the interest. This is the place for those who can't stand the overpopulated hives of the Sprawls, or for activities too onerous to do around others. Slavers, scavengers, rebels, raiders, or those who truly must not be found. They offer slightly better odds of economic mobility but at a much greater risk.
Far outside the filtered Sprawls, the rest of the Earth is generally in ruins due to ecological disaster and depopulation. The air and water are toxic, with some exceptions (e.g. Bayou Riche or Adelaide). In most areas, nature has reclaimed our old spaces. The people who do reside there are most often living a semi-primitive life, making cave paintings in the husks of abandoned arcologies, or hunting stag through the tree-caves of suburban ruins.