For thousands of years other cultures have recognised other genders. The Hijra in India, Two-Spirit in native American culture, Bugis in Indonesia, and various incarnations of lady boys etc in Thailand. Navajo culture recognises five different genders and then you get into hermaphrodite, androgyny and all sorts of variations of X,Y Chromosone combinations.
Basically the assertion that there are just males and females isn't true and history, culture and human biology backs this up.
What has happened in western culture is that people have been framed into these two genders when it's clear that there are loads of people who just don't 'fit' and for those people I can only imagine how scary and frustrating it is to have people yelling obscenities and making all sorts of derogatory comments about them
I agree with you that there needs to be protected spaces for women, because like all of these things, they are open to abuse. And I also think children need protecting from invasive procedures and medications around hormone blockers/ and or surgery. But taking the Trump approach of just trying to deny it exists and cutting off all support and funding is just misguided, blinkered and cruel.