I'm quite sure if you spend money on the same goods like during that day - you can sustain a family. Small house with asbestos, little amount of home appliances, basic small car, no food delivery, no AC etc.

I know a decent number of single income families and they even have A/C!

You do have to intentionally budget but you can raise five+ kids on a single salary if you want to.

This is an outdated view.

The essential costs - housing, healthcare and education - have far outpaced inflation while the cost of food and appliances has not. How can a single income compete in buying from the limited supply of houses against dual incomes?

Community college is affordable. Small 2bd apartment is affordable. Old small car is affordable.

I don't find these statement to be true.

Like $3700 average annual tuition fee isn't affordable?