My parents were very literally baby boomers: their dads came back from World War II, got married, and had them in the late 1940s (in addition to other kids).
My mom grew up on a turkey farm and had to do chores before and after school every day. For Christmas she would get a doll and an orange. They had a party-line telephone all through high school. She was able to go to college and get a job afterwards, but had to supplement that salary with additional part-time work (wallpaper installation, sales, piano lessons) until she was in her 40s.
My dad had a more middle-class upbringing but his own dad was on the road 250+ days a year working in sales and rarely got to spend time with the family. He went to college and eventually got into sales as well but only after working as a housepainter, a nursing home orderly, and in a chemical factory. The stagflation of the 70s absolutely crushed them; then the Bush recession in the early 90s caused them to lose money selling their house when we moved. They are in their late 70s now and I think finally paid off their house a few years ago.
There were definitely resources that they had available that were much cheaper. College and housing would be the main ones. But salaries in a lot of fields even for college graduates were terrible, and the US went through two major recessions in their 20s and early 40s. There is a ton of economic idealization of the 1960s-90s that just is not accurate.