It is a little nuts, but there are three points that make it a little less nuts than it first appears. (1) Inflation correction. If technology makes tomatoes c

It is a little nuts, but there are three points that make it a little less nuts than it first appears. (1) Inflation correction. If technology makes tomatoes cheaper, now dollars are worth more, counted in tomatoes. Technology is almost by definition deflationary. Economists do try to correct for deflation and inflation in these statistics, though everyone admits it's not possible to do a perfect job. I think this correction partly addresses your concern about measuring goods vs dollars. Inflation measurement tries to keep the ratio of tomatoes to dollars accounted for, so that when we measure dollars, we can do inflation correction to translate into tomatoes. (2) Elasticity. If the cost of tomatoes goes down, then presumably the quantity of tomatoes produced will rise in response. This may increase the overall value of tomatoes produced (though it also may not). Over the arc of human history, technology that makes things cheaper to produce has tended to stimulate overall production. E.g., we work longer hours than many hunter-gatherers. (3) Objectivity. Many economic measurements fail to get what after we really want, which is how much happiness are we producing. But since happiness measurement is even more fraught with error, counting up widgets is hopefully not too bad a substitute. Although it is theoretically flawed, in practice I think it clearly succeeds. The people in countries with high GDPs seem more prosperous than the people in countries with low GDPs. But yeah, GDP is flawed. A state with awful weather where everyone needs to work to air condition their homes will have a both a higher GDP and a lower quality of life compared to a state with great weather.