I somewhat relate to this from a bit of a different angle.

I'm pansexual, so truthfully, I don't actually care what my partner's gender is itself, but I have a lot of standards which are not inherently related to gender per se. Far more women meet these standards than men, so in a sense, it makes me de-facto exclusively into women.

To give some examples, I'd love a partner who is vegan, has long hair, and doesn't have toxic masculinity. A man has the capacity to have all of these traits obviously, but if you think on the chances, I guess that narrows down the gender of my dating pool to be overwhelmingly women.