Look at the lives of people who live in the large cities of Africa surviving on $3 a day. They consume less because they can't afford to do otherwise. They live in poverty. Their reduced per capita consumption does not stem from, as is subtly implied by these arguments, some simpler way of life that we could try to get back to if only we strived for simplicity. They just can't afford to replace their (for example) broken, hacked, and welded 30 year old bicycle rim that serves them poorly. When the opportunity arises to afford a new rim, they do it. They consume by the same processes we do.