Parts are large and practically self-explanatory. A cracked bearing is visibly defective. A burned out starter won't crank. My tractor has never caught a virus. In retrospect, I saw that the day had neatly compassed the new and old economies, while highlighting the truth that the really important stuff endures.
Physical work requires physical strength.
Iron and steel require enormous energy for extraction and manufacture. But once made, a tractor holds its value, and incidental repairs don't come close to the cost of replacement. Intellectual work requires intellectual nimbleness. Easing the drudgery of manipulating symbols requires a palimpsest or a magic slate. Pencil and eraser were a vast improvement over charcoal or ink, and the pixel is better still.