The gender pay gap is a statistic that requires some nuance to evaluate and I think your analysis is reductive. Yes, if you add in controls it lessens, but why? Why do women as a population have systematically lower levels of work experience? The pay gap is an assessment of how well our society is structured to allow people of both genders economic opportunities.

Shouldn't choosing to raise a family account for the experience gap? Yes, this is an example of one way that we've structured society so that women tend to have fewer career opportunities. IMO, there is not a good reason men (as a demographic) shouldn't be spending an equal amount of time raising children.