One thing going on is that the major lifestyle and utility improvements of the past generation-really cheap access to communication, information, and entertainment-are overwhelmingly available to pretty much everyone. On the one hand, this means that recent economic growth assessed in terms of individual utility and well-being is much more equal then when assessed in terms of income. On the other hand, it means that access these benefits seems much more like simply the air we breathe then as a marker of class status, or achievement.
Basically, this means that things that used to be markers of an increasingly well-off lifestyle are now commonplace. It's no longer a luxury to have things like a cell phone or a flatscreen TV, let alone running water or electricity or a car.
That isn't to say that income inequality in the United States isn't a huge problem, but most of our citizens are really rich, comparatively, on a global scale.