Look more carefully into the rural areas of DRC and you will see little huts and hamlets everywhere, even in the jungles there are clearings clearly inhabited by human. There are also larger towns scattered around that appears to be yellow, earthy spots on the landscape but if you zoom in you can see its houses. Each of these houses can likely house an entire family.

Also keep in mind the US is very sparsely populated after all. You can easily drive hours in parts of the western US (never mind the parts you cannot even drive through, or Alaska) without encountering a single human settlement.

I drove for almost an hour last night in Oregon without seeing another car. This was on a highway at 10pm not far from a city of 60K.

People forget how rural the US can be.