I will reply to the rest with more links when I get time but I'd like to point out your fixation on the bottom 10%. The bottom majority that i specifically mentioned is not that 10%. Wealth inequality is not just a matter of homeless and destitute vs middle class or war-zones vs first world but the vast majority of normal working people vs an absurdly small concentrated minority.

>I suppose people becoming wealthy is concentration, but this is a good thing.

Would you apply the same logic for oligarchs in a failed state? Or robber barons in the oil rush? I suppose you wouldn't be the first. When the average person of this generation finds themselves in an increasingly more financially precarious situation than the one previous that analogy feels less hyperbolic. Especially when we actually try to consider the class of people with the most leverage and influence over political and economic decisions and their role in this process of wealth accumulation, instead of pretending economics is a natural phenomenon like the weather.

>It means the system is delivering

The truest thing you've said so far. Shame about who its delivering for.

So far your only criterion of a healthy economic system is if the most destitute in the world are worse off than before and insofar as it can be met you dismiss the more significant trend of wealth concentration as an insignificant happenstance rather than a fatal flaw.