The concentration of wealth is a problem. And as the Government (at all levels) controls more and more of GDP the problem gets worse. There’s a REAL correlation there.
If we had an environment of honest fair competition the differences would collapse. As we transition to crony capitalism (fascism) it will get worse.
I was poor as a church mouse growing up. I never looked in envy on the rich. I looked at them and thought “how do I get there.” And, I worked hard and succeeded. If I had been willing to work harder, I would have succeeded even more. If you aren’t where you want to be, blame it on your own efforts (or lack thereof). EVERYONE in America still has the opportunity to succeed. Concentration of wealth goes away when the masses focus more on their own efforts rather than handouts!