Women aren't nearly as motivated as men to work as much. That is solely one of the biggest determinants of the wage gap as it exists. But the whole impetus is WRONG. Men get paid a fraction in the Fashion and Modelling industry and it is not for nothing. Likewise, women outnumber men in the primary to secondary teaching sector. Again, the same is true for Nursing. Men OTOH shamefully outstrip women in the construction, menial jobs sector.
All of these have deep rooted biological biases. You can read James Damore 's memo to understand a good deal of it.
ALL companies including the ones who pursue DEI are aware of these elementary facts. Yet, they actively lobby and pursue DEI policies to UP the costs significantly for small cos thereby imposing severe disadvantages upon them to sustain their own dominance. Guess where the same principle works again? Minimum wages. Cos like Amazon lobby and are vocal about raising minimum wages because small mom and pop stores can't afford them but they can.