The problem with the argument that uneconomic factors have improved is not just that these are hard to measure but that a lot of folks have an interest in fudging the measurements.

Inflation adjusted wages have been quite stagnant while measures of inflation are rather dubious to say the least. My old car is indeed a bit more reliable than my previous old car but both were reliable - I can't see that compensating for more or less everything costing more relative my relatively fixed income.