Because if by "we" you mean, anyone who has a blue collar job and/or "just" went to a state school, and if by "rich" you mean, able to afford a house,have the luxury of one partner (usually the woman) to stay home, medical costs in any eventuality, send their kids to college, then you are sadly mistaken.
Then wages have gone wayyyy down. And then if you factor in things like employer pension plans back then.. well, crazy further.
Now if the argument is "well we have more luxuries".. I mean, sure.. but it just seems an impossible task to raise a family and pay for home/healthcare/education compared to what it was even 30 years ago.
And have wages really gone down? As a whole, we're richer than ever. We own more possessions, have bigger houses, spend more money on luxuries, etc.