More women work part time, which is probably the basis of the “equal work day” argument.
If the “equal pay” movement makes progress, we could see part time jobs eliminated in favor of full time jobs with overtime - which would cause a massive exodus of women.
I had a liberal friend (I know, I know) who loudly parrotted this constantly.
The truth is, men usually make more than women because men engage in industries of occupation that are physcially demanding and dangerous and pay accordingly more.
I’m not suggesting there are no women lumberjacks, miners, law enforcement officer, firefolks, etc, but the numbers on work requiring a degree of physical ruggedness is overwhelmingly male, and that’s where the higher pay comes from.