I don't know when this practice died out, but it used to be routine for homeowners to take in boarders.
People could generally meet their basic needs because those were the only things they spent money on. Life was exceedingly bare-bones. Houses were small. Your life revolved around your job. You cooked all your own meals. You entertained yourself. The list goes on.
All of that said, house prices are alone just bad example. If you went somewhere with cheap land and no red tape, you could get a 70's house at 70's prices (adjusted for inflation) still.
One thing is that mom cooked all the meals. People rarely ate out. I know that was true in my family at the time. Eating out was a major, major treat. Entertainment was going out the door and joining up with the neighborhood kids. The house was tiny.
It all was perfectly normal.
Food has also gotten much cheaper relative to what it was in the 1970’s. Some would argue that it has also reduced in quality.
But if you add up all the plusses and minuses the two income family today has less disposable income then the single income family in the 1970’s when you exclude the cost of transportation, healthcare, childcare and housing.
It turns out one of the biggest drivers of home prices is school quality and income potential. So two cars for two jobs in a place you can find them and housing and childcare to ensure that children are safe.
The starter homes of the US Boomer generation are out of reach of the Millennials even though they are the same houses but now 50 years old.
Most of the houses have had additions built in by now, and extensive revisions and upgrades.
There are plenty of homes in the US that can be afforded on a single salary of a blue collar laborer.
Are these in the highly desirable coastal cities? Of course not.
People used to move to LA post-WW2 because it had cheap and plentiful land. It no longer does.
It is possible that you're just so rich their income wouldn't contribute to the family, but income is always useful - otherwise neither of you would be working.
that sounds quite reasonable to me, considering the vast decrease in material living standard in the US for the last several decades. there was an interview with someone who lived through the 70s that was saying a painter back then could afford to buy his own home, have a wife that didn't work and six kids! today, a single painter can barely afford to rent a single bedroom, let alone support a whole family and have a house.