The average household size (persons) has been declining and the average house size (Sq.ft) has been climbing. The average person has certainly much more square feet for themselves.
Prosperity is generally defined as the amount of work hours you have to do to make ends meet. That number has skyrocketed. In that era you could put yourself through college delivering pizzas. In 1950 you had to work 2 days per month at minimum wage to rent a house.
I think the size of one's house is one of the archetypal measures of "prosperity" and it's been exploding over the past 50 years. More generally, the problem with these little anecdotes is that they're not normalized to anything. Anecdotes along the lines of "you could afford X on Y hours of minimum wage work," for example, ignore the fact that almost nobody earns minimum wage today: https://fred.stlouisfed.org/graph/?g=1M09. The percentage of workers earning minimum wage or less (some workers are exempt) dropped from 15% in 1980 to just 2% today.
These anecdotes also ignore numerous other parameters. For example, households are much smaller today than before. So looking at "median household income" understates increases in income for the middle. Without adjusting for decreased household size, inflation-adjusted household income went up 16% from 1970-2010. Adjusting for household size, it went up 34%.
Likewise, people are more likely to be single parents, etc., today, which impacts economic prosperity. From 1971 to 2011, married people with a spouse present did well: https://www.pewsocialtrends.org/wp-content/uploads/sites/3/2.... The percentage of such adults who are low income stayed flat at about 21-22%. But the percentage that qualify as upper income grew from 14% to 25%. For those who have never been married, the opposite happened. Low income rates went from 22% to 34%, and upper income rates stayed flat at 16-18%.
Are incomes inflation adjusted? The average income when I was a kid was $50k per year, about the same as it is now, except that $50k has 50% less purchasing power today. $50k today is the equivalent of $25k 30 years ago.
Here's probably a more interesting statistic. Women's labor force participation rate hit current levels around 1990-1995, when I was a kid. Since then, the median inflation-adjusted income for a married couple with two people working has increased more than 20%, from under $90,000 to over $110,000: https://fee.org/media/30584/census3.png?width=600&height=409....
