At the risk of being branded misogynst...
... there are a number of problems in society that make it unlikely that there will ever be full equality, at least in the very misleading median pay gap measurements.
The problems are mainly about the biological nature of the family, i.e. women are much more intimately involved with the process of having a family.
Let's consider the best case scenario. A woman is in a company, being paid the same for the same role as their male counterpart. The woman decides to have a child, and then works up until a few weeks before the baby is due. She has the baby, and then takes the maternity leave offered, and stays off work for a further 8 months or so, as she is encouraged to do for the sake of her baby.
Let's assume she can return to the same job she had before (which isn't always the case).
She's now been away from the workplace for three-quarters of a year. Her male counterparts have had that extra service, seniority (and probably pay increments), and the woman has to come back to re-learn certain aspects of her job. And in a fast moving industry such as IT, she's also got to catch up on the new developments. If she's in a customer facing role, her customers will have got used to a new face, and she will have to get back in with them, or find new customers.
If we assume that her partner will really share all child care duties, this means that she is actually likely to be a year behind her male colleagues. And if it is not equal, this is another impediment.
Multiply this by two or three, and this is the barrier she has to overcome.
But more realistically, career women end up by choice having their children close together. So it may be that instead of several one-year gaps, one per child spread over several years, they end up with a single two or three year gap.
If this happens, it will be much more difficult to catch up her peers, and their original job role may not even exist! So returning to work will be much more difficult. Also, in the past, Women have been able to retire earlier than men, removing experienced women from the pool of talent.
Add to this the significant number of women who, because of unequal child care or just personal preference, decide to down-grade or completely sidestep their previous careers, such that they will be unavailable to be considered for high level jobs, and the situation gets worse.
Another aspect of high function technical jobs is that the climb to the higher reaches of the board takes 20-30 years, so the women able to be appointed to these roles now will have joined in the 90's, a time when there were fewer women in technical jobs. We will have to wait 20 more years for any current actions we take on recruitment to kick in.
I don't think that there is any real surprise that many of the women currently high up in industry have chosen not to have children, have had them early and restarted their career in their early 20's, or have been able to out-source their child care at the risk of damaging their family life.
Until we have a complete shake-up of society, this pattern of family life will persist, and I can see very little that will significantly alter this in the near future.