I agree with you I think innate behavior is tricky. It’s very difficult to nail down what is instinctual and what is environmental, and looking at global cultures isn’t really a pure indicator since those global cultures have been interacting with each other for centuries.
The other issue is that if you can dream it up, there is a probably a culture, or sub-culture, out there doing it. While it may be an extremely small group of people, say less than 10k people, someone is doing things differently.
But if we want to be anthropologists about this, then tribal people might give us our best clue, and many indigenous tribes don’t assign gender roles. While the hyperbole would suggest otherwise, genital mutilating “tribes” are typically more modern offshoots of contemporary sub-cultures. Again, there are always exceptions, which makes the whole “innate” thing very difficult. I think to try and simplify it is an exercise in futility.
How that pertains to female sexuality and equality? In my humble opinion, if it feels unjust, then it probably is. It might not be unjust for the reasons we think, but human beings are usually pretty good at knowing when their getting fucked over.
Personally, I think women in western society to bring a different quality to parenting than men, and vice versa, but I’d like to think that both energies/forces/influences are equally valuable. But where one is unavailable, the other is capable of stepping in and providing it in some form. I’m living proof of that.