This doesn't really function as a counter-argument, as every bit of it is applicable to you, too:
The billions of other women don't give this topic the in-group justifications and single-mindedness that gender critical gender ideology campaigners do.
I assume the billions of other women know a woman when they meet one. Not everyone believes (or cares about) what you do.
As such, it sidesteps the point by reducing something more complex to a matter of personal perspective (while, ironically, 1) not acknowledging the dual applicability of your comment, and 2) assuming the indifference of billions to suit your own narrative - I could say this actually exposes the reductive nature of your perspective, thereby reinforcing the validity of my concern).
Anyway. The point is, we have two different views here on what "woman" should mean. So, how do you argue against mine in a way that isn't just, with mildly entertaining irony, "Not everyone thinks the way you do, and many aren't even aware of their own redefinition in 21st-century western English, so (implicitly) back to why what I think has primacy?")
Instead, I'm interested in how one actually, ethically, chooses between your, and our, interpretation of "woman"?
My argument is that it feels unethical to remove from western English vocabulary a descriptor for billions to instead replace it with something misaligned with their conception of themselves. I give an example of how that has the concrete effect of hampering our ability to refer to others; it also feels wrong as regards them (to use an analogy I think you'd appreciate, not unlike misgendering a trans person in their absence).
As such, I argue for a "woman" and "transwoman", as this enables both demographics a descriptor and political identity. Anything else feels undemocratic in our own limited context, and unethical - and also impractical - on a global and historical scale.
What's your argument for melding these two descriptors? Practically and ethically? Logically? Philosophically?
As opposed to primarily personally?