It is leftist trope designed to pit people against each other.
In fact, I question the whole premise, that women are paid 70 cents on the dollar, or whatever the current figure is.
Use 70 cents as an example.
If women got paid 70% of what men earn, theoretically, no man would have a job anywhere. Why? Because the businesses would simply hire women for 30% less, save lots of labor costs, by not employing men at all.
As is true of many issues, liberals take some one liner, such as “women are paid less than men”, and do not investigate any of the nuances or complicated forces which make up our labor markets. They have no clue how wages and salaries for jobs are determined in the first place. They simply proclaim “woman are paid less” and say it must be discrimination. No investigation of details, no understanding of where this notion of unequal pay comes from. The liberals never even mention that paying a woman less for the same job is against federal law.