Yes, the poorest among us are materially well-off, by any historical comparison. Yet the article speaks to how we're doing psychologically and spiritually. It's a little glib to tell people they'd better get happy and appreciate how much better we have it than ye olde folks of yore.
Trump has gotten this far by stirring up rust belt fears of human obsolescence. Less-educated white males are seeing their place in society disappear. If you don't think "the rest of us" have to care about that, wait and see the response as autonomous vehicles take out the trucking industry.
Even if Trump loses this time, the same underlying sentiments will produce more Trump-y candidates in the future, unless something can be done to create real change and ways for all sorts of people to be active and valued participants in our society. It's important to recognize the pain and suffering behind the fear of being unneeded.
Interesting questions abound:
If prescription anti-depressants worked, wouldn't Americans be the happiest people ever?
We already know behavioral advertising changes one's perception of oneself -- does that shift affect well being?
What's the psychological cost of commodifying one's special moments as social media posts?
How do we engage undocumented kids who feel sidelined by the lack of paths toward rewarding careers?
How do our attitudes toward birth, death, and caring for the very young and very old work against well-being?
Why do we measure economic health of our country without reference to the distribution of ownership of capital? (We carefully measure the number of wage slaves, but who's measuring the number of people who own productive enterprises? Stocks are too far removed from "productivity" and shouldn't count.)