If you're an investor (and everybody's an investor whether they like it or not) the question you should be asking is what things will be like in ten years.
That said the article (like pretty much all economics that comes out of The Atlantic) is pretty silly. The dire condition of the American middle class is completely the fault of the US government. In the last 30 years (while China has achieved world historic growth) the US has dumped trillions into wholly unnecessary wars and giveaways to international investors. The $20 trillion dollars the US government has wasted is the greatest malinvestment in the history of the world. All the money that should've been spent on vital innovations and critical investments and infrastructure was used to blow up brown people and inflate asset prices. 2008 was just the beginning; the consequences of this extraordinary malinvestment will take decades to ripple through the global economy. The 9.9% or any other arbitrary percent of Americans are only to blame to the extent that they haven't overthrown their government and executed a few politicians. Over and over electorate have failed to correct the system and so politicians like John McCain -- who helped push America into the greatest crime of the 21st century -- are widely lauded instead of arrested.
[1] https://www.ft.com/content/51771766-7c7c-11e7-9108-edda0bcbc...
[2] https://www.vox.com/science-and-health/2018/5/22/17376536/fe...
[3] https://www.stlouisfed.org/~/media/Files/PDFs/HFS/essays/HFS...
[1] http://www.aei.org/publication/todays-new-homes-are-1000-squ...
[2] https://en.wikipedia.org/wiki/Home-ownership_in_the_United_S...
[3] https://www.statista.com/statistics/184272/educational-attai...