There were very few people this applied to.
The real reason is the corporate tax rate. It was 52%. Today it’s 21%, and it’s effectively close to zero for many corporations with the tax loopholes used to avoid taxation. Shell corporations, deferring taxes, what have you.
So the US has lost more than 50% of the corporate taxes collected since the ‘50s.
E: the decline in tax % is pretty closely followed by the dramatic rise in CEO compensation.
The wealth being funneled to the top by cutting corporate tax got us the billionaire oligarchs we’re dealing with today.