Food and shelter aren't natural resources. They are things that you produce using natural resources.

"Civilized" societies use far less land per person to produce food.

This may be true now, but it's only been very, very recently in history that food surpluses are a certainty.

Until a century ago, frequent crop failures, disease, and other ailments were a hallmark of sedentary societies.

I think the original criteria was "easily accessible at a low tech level". Civilized societies are efficient and can access difficult-to-reach resources. It seems the OP's argument is that to be a tribal society you need easier-to-access resources, resources that are now controlled by the civilized society.