Quintiles are pointless. The top 20% isn't much different than the bottom 20%. The middle 80% is pretty much middle class -- especially in the EU, where there's slightly less poverty (actually in the US the poverty rate is lower than the EU, but the "technical" poverty rate isn't very helpful -- there's differences in access to healthcare and education, not to mention costs of living).

The difference in quintiles is mostly age (especially wealth, but also income). The top 10%, 5%, and 1% are more interesting to look at. These are almost entirely laborers (in the US). In the EU, the top 5% is dominated by aristocrats.

WRT to the income chart, the top 1% is mostly laborers (in the US) but is completely skewed by the top 0.001%. It's easy to mislead with that.

Also, I think people are equally concerned with income inequality and wealth inequality. This is only half the picture. In the US, laborers can and do accumulate large sums of wealth. This doesn't happen in the EU.

Some things that I'd be interested to know -- in the US, 50% of people spend one year in the top 10%. I'd love to know what that is in the EU. I'd also like to see 5% and 1%. I'd love to see what percentage of people in the top 10%, 5%, 1% , and 0.1% were born there.

Who cares about the top 20% vs the bottom 20%? It's the difference in between being a waitress and being an electrician. Almost anyone could do any of those things.

The bottom 10% is interesting -- those people are literally poor. How many of them are poor simple because they were born there? The bottom 20%, not so much. A lot of people work low-paying service jobs because they're more interesting than mid-paying desk jobs and less risky than high-paying blue-collar jobs.

The top 5% is interesting -- especially in the US -- because anyone can, theoretically, work their way there (obviously, it's a lot of luck, but it is still mostly laborers, and the difference in wealth/income is considerable).