I'm assuming "effort-hours needed per unit of purchasing power" is how much work is necessary to achieve a standard unit of purchasing power, right? If that's the case, it's far more likely that inflation has negatively impacted this standard. That assumes it's expressed in currency, which I may be wrong about, but I'm welcome to any correction.
As far as the on-paper point: more people have greater access to more goods from a wider variety of sources than at any point in our prior history. I don't think you can argue that. Medical technology has made unbelievable strides in the last 30 years. Decentralized methods of water purification and power generation are available for relatively little expense, and they continue to drop in price. You'd really have to stretch to make the claim that the standard of living has either remained stagnant or gone down. I don't disagree that governments tend to want to skew statistics (just look at the US "unemployment" figures or the actual debt liability), but that's not the only method of discerning the truth of their conclusions.