The rent was 12% of his income only. Which means a bachelor with a middle class job could easily rent an apartment with 4 bedrooms and 2 sitting rooms. LOL
Everything was much much cheaper. Except exotic food groceries.
Rent was 12% because rents generally were lower, but eg clothing for sure was way more expensive.
You can compare to the maid and see how she was doing.
How long did the maid have to work to be able to buy a shirt, vs how long do you have to work to buy a shirt?
Depending on where you work, not that much more. But you don’t get to spend all of your gross salary on cars.
One colleague of mine wanted to keep saving and pay for an apartment in full; he didn't manage to, even though he was more senior (read: earned more money; also he lived alone, could save more than I could). What happened was that prices increased faster than his savings rate - effectively by waiting he lost money, and eventually gave up and took a credit. Now... there were multiple factors for the increases in the housing market, credit being available was not the only one, but I do believe it was one of the main drivers.