One issue to consider, as a partial reply, is the difference between "absolute" and "relative" wealth during the difficult years. It is true (basically) that common wages have stagnated since about 1973, and income inequality has grown more severe. (This can be attributed to many factors - mechanization of labor, the entrance of women fully into the workforce, policy decisions, etc.) So, in a relative sense, many are "worse off" than before.

However, in absolute terms, you could argue that wealth has increased noticeably. As an anecdotal example, I personally can afford, with a fairly humble income, a much materially richer lifestyle than a similarly placed person would have in 1970. I live in a nicer and larger home than would have been available to me back then, with a huge, inexpensive TV that gets 30x the number of channels, a portable phone that is tiny, a computer which links me to the internet, a microwave oven (still neat to me!), access to tons of media at affordable prices, and continually cheap food. So, in absolute terms, I am much better off than my 1970 equivalent would have been.

It should also be noted that the same economic system that created the income inequality of today also helped develop and produce (cheaply) the items I mentioned. While I am not giving the current system an unqualified endorsement, there is an argument that the free market policies of recent years have contributed to that expansion of wealth for the average American. TL/DR, we're making the same amount, but getting more for it.