But where are better options?
Not one nation in Europe is both better off and more politically and economically free than the US. Australia and NZ aren’t doing much better at all, Russia is still doing way worse and is still quite a bit more dictatorial.
A few here have mentioned the Japanese and the Phillipines which are great for foreign expats (though of course when you are a local it is an ENTIRELY different situation). But they have enough room for maybe a tiny fraction of the Americans that might consider moving, if that.
http://one-salient-oversight.blogspot.com.au/2009/03/income-taxes-australia-vs-usa.html
You may find the discussion on this site of interest.
Paraguay
But most people, especially the one referred to in the article want to just live abroad for other reasons, not just for economic.
I’ve got a friend who’s been working in Hong Kong for years. He wasn’t really an expat but he’d landed there for one job and stayed through a couple of changes, finally got tired of all the visa renewal crap and went for citizenship. Most were probably on a similar path, they’ve found themselves a new home and eventually it’s just not worth the trouble to keep officially being an American when you have no intention of ever living here again.