Some more thoughts on the privilege that I think influences some - many - of those (and in particular, many women - see how I need that word?) who are arguing for the collapse of our ability to distinguish clearly in language between male and female humans...:
One of the clearest examples of it that I've seen was earlier in this thread, in the earnest suggestion that (paraphrasing) maybe an ancient woman warrior was seen wholly as a man. Not in the sense of being mistaken for one (which would be unlikely enough), or in the sense of masquerading or behaving as one, or even by being generously gifted with honorary membership, but, instead Being Seen As A Man By Her Society, in the most absolute sense.
But how could this be? Truly? Just think about it.
It's only recently - terrifyingly recently, really - in human history that humans (and women, in particular - there's that pesky word again) have enjoyed the privilege of being liberated, relatively speaking, from their physical bodies and differences. It's because of birth control, equalities law and a growing detachment from our physical realities through the industrial and electronic revolutions (etc.) that this has become possible.
Prior to this, the suggestion that a woman could be seen as entirely a man, with all the physical advantages that that entailed, is surely, regrettably, laughable - again, the stuff of children's adventure stories. What - her relative physical weakness an overlooked irrelevance? Her vulnerability to impregnation of no significance? No distinction made between her and "actual" men at all?
Let's face it. Whether she was travelling, fighting or at home alone, in a world reliant on physical strength and subject to brute force, her physical reality represented an unavoidable truth that she simply couldn't - and that those around her just wouldn't - deny. Certainly, they wouldn't - couldn't - re-conceptualise what it meant to be a man or a woman to expand these categories so as to include her in the authentic sense apparently intended by PP.
The fantasy that they could do this is, to me, just another indicator of the unthinking privilege enjoyed by many in the western world who propound this ideology. It does seem significant to me that, whereas other manifestations of gendered difference that "our" trans advocates often attempt to appropriate in the "we've always existed" slogan - eg. fa'afafine - are actually additive approaches to accommodating this difference. They don't seek to dilute, negate or outright deny the concept of man and woman as PPs on this thread do. Instead - tellingly, I think - it seems, largely, to be only the most affluent capitalist societies that feel able to do away once and for all with the actual terms "man" and "woman" themselves. And even within these societies, it's the more privileged - the middle and upper classes, and the educated elite - that are more likely to argue for this. That is, those who are furthest removed from the realities of being physically vulnerable in a volatile environment, or struggling to pay for personal hygiene products, or enduring an unwelcome familiarity with the dodgiest public toilets in the most rundown corners of town.
And this naive, capitalist privilege, in which what one says, is what one is, and what one wants, one expects to have, and individualism is all... Honestly, it's yet another reason why I believe it's actually more important than ever that we hold on to our ability to name women's sex-based needs. Because it belies a frightening complacency that makes us vulnerable. We can't afford to rely on our current level of privilege - our current social structures, and associated sex-based protections - lasting. Please, let's not start dismantling these ourselves even before external forces (the environment, competition for resources, war, a declining population) do it for us!
Do you really think there's no distinction between the vulnerability, and fates, of women and of men in the event of famine, natural disaster or invasion? When a group, or society, or humanity itself is threatened in one way or another? Of course there bloody is. The difference is immense.