Actually, most could still live a post WW-II lifestyle with a single wage earner. The problem is that we now think we are en led to much more.
The average post WWII family.
- lived in a wood frame home less than 1000sf
- kids doubled/tripled up in rooms
- the house was not air-conditioned
- the only had one car that the family shared
- they cooked fresh food from scratch
- eating dinner out was for "special" occasions
- they might have one TV
- they had one phone that everyone shared
This was your middle class that payed the bulk of the taxes.
People that live like this now are considered "poor" and don't pay taxes.