If you cut out everything we have they didn't - cable TV, Netflix, computers, internet, cafes, restaurants, Kindle, better choices in grocery food and alcohol - and ate the sort of cheap food people lived on, things like meatloaf and crappy ingredient dishes, I reckon it would be entirely possible.
The only thing that is prohibitively expensive today vs 1980 is housing. The reasons for that are multiple, but mostly NIMBYism.
Again in constant dollars, health care has seen a more than fivefold increase since 1970, from under $2000 to over $10,000 per capita. Constant dollars, mind you.
Health care and education costs are more or less fixed and unavoidable. They're more like fees than taxes, flat no matter the income.
Flat if you are lucky enough to be healthy. Enormous once you actually have an issue, like a complicated pregnancy, or something that requires an MRI.
You can't pay less to get the world class care of ten years ago. Name one other sector you can't pay less for lower quality
However, it's housing - in the bay area in particular - that makes it look very impossible. For a relatively modest 1 BR apartment in SF, I'm paying close to half my after tax, after-401(k) take home, as a senior engineer doing relatively well.
If I'd need to pay 50% more to have a 2BR (at a minimum) for a wife and a child or two, that leaves a very small amount (for what's now twice as many people) to live on; roughly 10% of my base salary. It looks nearly impossible.
If you are extremely frugal (no restaurants, no vacations), if you get really lucky in finding housing, and most of all if there are no big surprise expenses (e.g. medical ones), MAYBE.
But none of those caveats applied in the case of my father; his standard of living was higher than mine is now.
Of course, if I were to move to another market, it's quite possible. I might take a 20% pay cut but if real estate is a third the cost than suddenly it doesn't seem like an impossible scaling issue that it currently is. I might even be able to afford a car.
The cost of activities for children has skyrocketed beyond belief compared to 40 years ago.
But if you're talking about any sort of instruction I'd say the prices have tripled. If you're talking about something like organized hockey? Prices are astronomical.
Kids basketball consists of 1) kid. 2) shoes. 3) ball. And you only need 1 ball per group of kids. Ditto for soccer (futbol) A jersey is optional.
Hockey requires a bunch of pads which will be changed out every year or two as the kid gets bigger. Hopefully they have a sibling that can make use of them otherwise it's a sunk cost. Then there are broken sticks, broken teeth, hockey bags, ice time -- non-trvial -- and it adds up.
Hell, the cost of replacement skate blades -- not including the yearly sharpening -- is more than the cost of a basketball and a cheapo pair of wal-mart athletic shoes: https://www.bladzskateshop.com/product/bauer-lightspeed-repl...
Also Netflix is really, really cheap and my computer cost me approx 800 USD and has lasted 5 years.
Housing (and in the USA, healthcare and college I suppose) are by far the most expensive things for most people and have soared in price.
All the other things are negligible in comparison - it's like the people going on about avocado toast.
Assume $120 annually for Netflix. A cost almost everyone assumes now, and most people have (58M subscribers in the US/~120M households in the US). $120 compounded yearly at an 8% rate over 18 years is almost ~$5k. Depending on the year attended that's anywhere between 2/3 years of a degree and half of a semester at a public institution (in today's dollars).
Point is, it all adds up. And taking your example; the most expensive things we spend money on are also inflating at an abnormally high rate. The money has to come from somewhere, and when it's leaking out $10/month at a time, it's sometimes hard to find and easy to overlook.
That as enough to support my mom and 2 children while also saving for retirement.
That standard of living now would require both parents working and being rather successful in their white collar careers. Even as a reasonably successful person in an advantaged field (tech), I can't imagine supporting an entire family.