Interesting thread. Life has changed so much in the past 50 years. Expectations have changed. Women now expect to be men's equals, whereas in previous generations it was assumed that housework and looking after children at home were a married woman's main role and responsibility.
Equality comes with a cost, unfortunately. Now that women have the same status as men, the available salary is split more or less equally between them. Previously it was more like 80/20, so the majority of men could earn enough to support a family on a single salary. I know that's a very simplistic argument, but it's the general gist of how things were and how they now are.
I had my children towards the tail end of "the old days". They are now in their 40s. For the first 6 years after the eldest was born I didn't do any paid work. I didn't have a lot of choice, as there was next to no childcare provision back then (but the truth was, I actually wanted to be a SAHM anyway, so was happy about it).
How did we manage to afford to live on only one salary?
Well, to begin with, when we bought the house the mortgage was based mainly on DH's salary (in the 1970s and into the 1980s, it was assumed that the wife would be having children and leaving work a few years down the line and so that was reflected in the mortgage offer). So although we had to tighten our belt when the children were born, it wasn't by a huge amount.
Secondly, our standard of living and our expectations were modest. We had no central heating, so energy costs were relatively low. We never went out to anywhere that had a cost involved. We ate cheap food from a discount supermarket (our dinner was often beans on toast. My lunch was often a pot noodle or a couple of slices of toast and marmite). Apart from underwear, the children had mostly 2nd hand clothes from the charity shop. Some of their Christmas and birthday presents were from car boot sales or handed down from cousins who'd outgrown them.
I used to buy bargain-bucket balls of wool and knit jumpers for the whole family.
Our TV was rented. There was no such thing as videos, mobiles, Internet etc back then, so we didn't have those expenses.
So much has changed! Nowadays mortgages are based on both partners earnings. People marry later and then don't want to take a step down (or several steps) in their standard of living in order to have children. They are naturally loath to give up the things they've become used to having, such as a warm heated home, new clothes now and then, holidays, meals out, takeaways, cinema trips, theatre, Netflix, nice phones, computers, a decent car etc etc etc.
Back in the late 70s/early 80s we had none of those things to begin with, so there was less to give up.