You forgot to address the part where men don't do their share of parenting, even in couples who go into it with egalitarian ideals.

birth defects

Most of which are easily detected before birth, and the vast majority of women who receive unfavorable test results will choose to terminate.

Human reproduction has always been a numbers game and process of elimination. Far more sperm and ovum are made than will ever meet, far more meet than will implant, far more implant than will be born, and until recently far more are born than will reach reproductive age, and some of those who make it this far still won't reproduce, hopefully they will have a positive effect on the species regardless.

Basically, with modern technology, we're just tweaking the selection process. Humans used to breed like rabbits because it was likely that at least a few of them would die-- and 40% of new mothers did, as well. What's worse, bringing life into the world only to be cut short or making sure the ones who would die just aren't born or simply never exist, in the case of contraception and other factors.

In a few decades the U.S. will be in the same boat as Japan-- low birth rate, low marriage rate, aging population. That's where we're going, there's already a shortage of elder care workers. The consensus seems to be that we will eventually turn to robotics to meet this need.

Millenials have already begun have children and a new generation is on the rise. The world will be a fundamentally different place for them than it has been for us. With the unprecedented change we have seen over the last 50 years, you cannot possibly suggest it will just end.

Especially not when it's quite known that there is little to no biological marker for ability, gendered or otherwise. As my experience has been that when women do go into traditionally male jobs/roles, they're usually better at it because, unlike the men in the room, they constantly have to prove it.

For example: My field is fairly equitable as far as gender distribution, but men still try to pull their bullshit in meetings. My response has always been, "Fine, I'll be better at it." I once looked a male colleague in the face and said, "Thank you for articulating my idea in a deeper voice, I'm sure everyone's heard it now," before reclaiming the floor. It works, but it definitely doesn't endear me to the whiney twats who expect me to act like a kindergarten teacher. A particularly bad reaction to this from a male-dominated leadership is, IMO, what probably happened to Ellen Pao and spurred her lawsuit.

This, of course, raises the question of why the fuck I or any woman should have to deal with any of this. Someday, we won't.