The fact is. In 1963 an act (Equal Pay Act) was created to prevent people under the same job title (without including bonus pay, overtime blah blah blah) cannot be paid different.

The wage gap graphs come from women working different job titles to the men they are compared to.

Since then. Over 4 other acts have been made to prevent any loopholes in the system.

If there is any issue in their company. They can simply file against them. And get a fat stack of "please dont tell anyone" money.

It is not the mens fault that they aren't taking legal action.

https://www.google.com/amp/s/www.history.com/.amp/topics/womens-rights/equal-pay-act