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.
We are long overdue for a hard reset. We need a new government with a modern democracy, then the assets of the top 0.1% need to be nationalized. Let them keep enough wealth to still be in the top 10%, but hit them hard and fast. Also, we should do what china does and to end offshoring by forcing companies to sell 20% of their company to the US government if they want access to our markets. Next, we need tax breaks for companies who spend more money compensating their workers than giving money to the parasitic shareholders.