I'm American. I've been in two economic classes: dirt poor (as in, more or less homeless, when I was a child, for a bit) and now on the low end of rich (net worth in the mid 7 figure range). I've seen both sides of this inequality, in America, personally. And new social circles that have opened up have given me something of a first-hand view of the "truly" rich as well.

I can list numerous ways that it's a problem, if you like. Here's one to start: "as long as people can move geographically" isn't applicable to those on the lower end of the economic scale. Your comment represents something generalizable about the rich, too: they are completely oblivious to just how hard and draining (physically, mentally, and emotionally) it is to be impoverished. I shudder to think what it's like for the poor in poorer countries.