That may be the case, but this article is about Americans. If we're opening up to the world, then just as well you actually have three options: move to a different country.
Which is also an option for Americans? Middle class city Americans are rich compared to middle class rural Americans, and the later are rich compared to other places in other countries still. Shrug.
Sure, I agree with that and that's my point. You can have your basic 1M house, but your 1M house sells for 1M at the end of the day. My 150K house will never be 1M. There's more involved than regional cost of living (such as salary, value of assets, value of work performed in relationship to where you live). You can move anywhere and some jobs will be the same or similar enough in pay, but my job will never pay enough for me to own a 1M house.
In summary, some of these wealthier on paper people you mentioned way back may in fact just be wealthier. They can also live a wealthier lifestyle if they so choose.