What's the problem with inequality after accounting for other societal ills and human psychology, such as:
Poverty
Lack of social mobility
Lack of opportunity
Widespread mismatch between worker skills and employer needs
Status competition
Perceived unfairness
Social comparison blues
Envy
Resentment
Mistrust of the System, eg capitalism
Suspicion of undeservingness, eg, illegitimate gains by the wealthy
Zero-sum understanding of wealth
Lack of hope/optimism
Constrained economic growth, e.g, due to misregulation, specific interests, monopolies
I suspect some will object that the other societal ills are exacerbated by inequality or that the above perceptions and emotions are onto something that really exists. To which I say: show me (with rock-solid evidence).
Causal attributions matter, because policy matters. Attacking the wrong problem makes for bad policy.