Real wages have been declining, or at least stagnant, since the 1970s. But overall compensation has been rising.
As the linked blog discusses, it’s controversial to claim that government mandated benefits constitute part of standard of living in the same way that voluntarily chosen goods and services do.
Standards of living consist in the set of consumer goods and services that people have to use. So the direct measure of standards of living is to investigate what set of goods and services households have and see how it changes over time.
While doing so is difficult and reasonable people can disagree in their judgments, it’s much clearer that capital accumulation in America has slowed since the 1970s.