That article from The Atlantic that you linked to basically says exactly what I'm talking about. We are much "richer" than we were before. But it has come at a high cost. We have become slaves to our own success. Most of our spending now goes to transportation and housing, whereas 100 years ago, it mostly went to food and clothes. The "necessities" take up a much smaller percentage of the total than they used to.
And the fact that salaries are falling relative to GDP should come as no surprise. A lot more of the GDP is generated with a lot less human intervention. We're producing a whole lot more food with a whole lot less farmers. Just because the average farmer can now maintain a 100 acre lot, as opposed to a 1 acre lot 100 year ago (numbers made up), does not mean that the farmer should be paid 100 times more.