> What am I missing?

Wealth inequality was previously at its highest point in the US during the Gilded Age, when the US was still on the gold standard and inflation was not as much of a thing (and deflation often reined):

* https://en.wikipedia.org/wiki/The_Great_Deflation

* https://en.wikipedia.org/wiki/Long_Depression

During the 1970s, US inflation was quite high:

* https://www.investopedia.com/inflation-rate-by-year-7253832

and yet during the same time period the wealth ownership of the top 0.1% went down:

* https://www.theguardian.com/business/2014/nov/13/us-wealth-i...

US wealth inequality only really started rising in the 1980s—as inflation went down. Further, as The Guardian graph shows, concentration has gone up from the 1990s up until now, even though the last few decades have had the lowest, and most stable, inflation numbers in history:

* https://en.wikipedia.org/wiki/Great_Moderation

So the link between inflation and wealth concentration does not appear to have any correlation according to the historical data.

I would hazard to guess that a more promising link to wealth concentration/inequality would be the cutting of tax rates (both corporate and personal) starting during the Reagan administration, and how it reduced redistribution of money to the lower- and middle-class.