Absolutely yes re children motherhood etc.
But quite honestly I think it is much more than just that. And it's often self perpetuating - industries with lots of men at the top are likely to continue to push men.
Law firms have done research on this (in their own businesses - and probably other professional services firms too) and, to their credit, are trying to fix it. For example - work allocation. Men often get the juicier, more high profile work, x1000 if the allocating partner is a man. He picks other men like him. The female lawyers might be working same hours but on smaller less high profile , less profitable, cases.
Similarly they have found performance reviews to consistently slightly bias against women - ie women overall, according to performance reviews, perform less well. Which, statistically, is unlikely.
Firms are trying to addresd this admittedly, but inbet the smaller ones dont.
then the double standards applied to woman. I have personally experienced these more times than i can count, as have most of my female friends and colleagues. eg a man can express dissatisfaction and/or a desire for more and he is assertive, proactive, ambitious. A woman does the same and she is demanding or ungrateful, needs to wait her turn etc.
Women are still somehow expected to do the "housekeeping" in many firms - organise drinks, tidy up, collect money at birthdays. Ditto pick up admin. I really hope this has changed but, for example, starting out 25 years ago in the city, when the bosses (male) didn't know how to send an email attachment or save a document it was always the junior Women who were asked to help them, never the equally junior men. We were de facto back up PAs.
Senior leaders who are Women are also often in support functions - head of hr, marketing, legal. Not part of core strategic decision making and commercials. And when they are, too often there's a "but...". See the "co-ceo" at M&S - supposedly the man and women were co heads but he was called ceo and she was called co-ceo. Not a shock when she only lasted a few years. see also eomen being promoted in to companies in serious trouble - so higher chance if failure from the start.
Women still often are paid less too. Sure, it's less blatant these days but happens a lot. Eg, a woman with less experience gets a "big" job - she gets it because the pay isn't good enough to get someone who is properly qualified (male or female). But then again, she's often set up to fail because she's not actually ready for the job OR she succeeds but is always behind on pay.
It is relentless and insidious and exhausting. Ans yes, lots of very welcome change is happening but bloody hell, we aren't there yet.