While I don't take any issue with what you have said, I do feel there are additional factors at play today that put financial pressure on many people. Many things are much more expensive relative to a typical income than they were when I was growing up. Health care costs, a college education, even food and other daily items have gone up. Where pens, pencils, and notebooks were what we used in school, if I understand what I have seen in the media (print, TV, etc.) now, students are required to have a computer, which is way more expensive than the simple things we used.
When I went to college (much later in life, in the 90s), I was able to pay my way through school with a full time job and school in the evenings. I had no student loans. I doubt that I could come even close for the same degree today. I honestly don't know what those who pursue degrees in fields other than tech, medical, the sciences, or law can do to ever pay off those loans.
More in line with your observations, with both parents working, eating out becomes much more the norm. On occasion, my wife and I will stop and pickup sub sandwiches at a shop such as Subway or Jimmy John's. When we considered how far that same money could go by just buying the materials and assembling these ourselves, and to our individual liking, we stopped that practice altogether. I can't imagine how people can continue to afford that on a regular basis.
When working full time, we engineers used to go out for lunch every day back in the 80s and up through the mid-90s. Around that time, we all stopped altogether except for special occasions such as somebody new starting or somebody leaving. We are talking about people with 6 figure incomes, not minimum wage earners. We felt we couldn't afford to go out to eat anymore.
When my youngest brother died, we all congregated in Los Angeles for the funeral. As we all talked among our siblings, we began to realize that the cars we each drove and the lifestyles we had were inversely proportional to our respective incomes. A younger brother, who is an attorney made the most money and drove a car his mother in law had given him, an old Ford Probe. I was next as an engineer and I drove a Toyota Echo (still drive that same car 10 years later) I bought used for $5k cash. I have now had the car for 16 years. The youngest, who had died, drove a brand new truck that we used to go places because it was big, expensive, and comfortable, and fit all of us. All those in between followed that same arc that I mentioned here.
As I recall when working full time, with both parents and kids, they needed daycare, and it cost as much as one of the two made working full time. I can see the rationale, because if they got divorced or one of them died, the other would need a career to keep afloat (at least that is my guess giving the benefit of the doubt).
Tony