Completely sincere question, how would you personally define a reasonable wage?
I think a better base line is targeting an individual. Healthcare, 400sq feet, electricity, water, gas, and UBI to cover food and leisure. From there job compensation can be tied to market rate and people looking for more can choose how they'll get it.
In the 50's and 60's, the US was basically the only developed country that hadn't had its homeland destroyed by the war. This meant that there was very little competition for US companies.
In addition, the labor markets were tight. Remember, half of the population (women) were not expected to be in the job market long term, but rather to get married and stay at home. There was outright discrimination against people of color. Thus you had very little outside competition for US companies, with tight labor markets in the US, this resulted in generally good pay and benefits for US workers.
The natural birth right is to compete for such needs and to maim / kill if necessary to obtain them. No safety or protections. Possibly small tribal units to operate beyond the individual.
A rational mind recognizes that the above leads to violence and associated negative outcomes. It also often poorly allocates resources and does not well adapt to the ability to engineer our environment for better outcomes.
Wages are also often conflated with a belief that there isn't a relationship between the average purchasing power over a population and the pricing of goods for said population. Supply and demand curves from econ101 exist to describe why that isn't true.
Thus another way of viewing wages, reasonable or not, is in terms of comparison among workers. The real question would be one of disparity between the have most and have least: how much more is one individual worth than another? Business expenses and such deducted beforehand, I couldn't even see Iron Man (Tony Stark) being "worth" more than about 100X what even the least worthy individual is; let alone a normal CEO. I find it extremely unlikely that normal worker wages have grown 100% since 1978 (or over any other timeframe) to at least keep parity with that measure...