People have been saying the same thing for 100 years -- usally when running against incumbents. It hasn't been true yet, and there's no reason to think it will be true now. You can look at a data series going back to 1790 (admittedly the early stats are debatable), and real per capita income growth over 20 years (1 generation) runs around 40-50%, for the whole period, with the lowest in the very early years of the republic. In 40 years it runs a bit over 100% on average.
Most of the people whining about how we're doing worse don't see that we're really "doing different." I grew up in a pretty average family for my town -- 900 square foot house, eat out twice a year, one black-and white TV. Travel 1000 miles away every 2 years. If you live that way today, you can do it with a much lower class job than my Dad had back then with a stay-at-home Mom. If you want a 2500 square foot house, eat out twice a week, 2 Plasma HDTV, go on vacation to at least to Fla or the Caribbean every year --- you need a lot more income -- and the average person actually has it.
I don't mean to rag on you personally, but that's the facts, and the "average" person is out there making it happen, every day.
Did you read the article? That's not true for the last 30 years.
This is also the first time a smaller generation has followed a larger one. It is also the first time in America's history that a smaller generation had to fund the previous larger generations retirement, and healthcare....