Data is the answer, it's just that so few people are willing to look at unbiased data. Although the start is asking a more measurable question.

some maybe-biased data for a steel man in [1]:

"The Census Bureau measure overstates current income inequality between the highest and lowest 20% of earners by more than 300% and claims that income inequality has risen by 21% since 1967, when in fact it has fallen by 3% ... In 2017, among working-age households, the bottom 20% earned only $6,941 on average, and only 36% were employed. But after transfer payments and taxes, those households had an average income of $48,806. The average working-age household in the second quintile earned $31,811 and 85% of them were employed. But after transfers and taxes, they had income of $50,492, a mere 3.5% more than the bottom quintile."

[1] https://www.wsj.com/opinion/income-equality-not-inequality-i...

Data is also a really, really potent rhetorical tool, because it is definitionally never complete (a map that fully captures a territory is the territory), and by those omissions, the data can be made to say anything at all in a way that looks unbiased.

What's the question I should be asking, and what data answers it? I'm genuinely asking