Earlier quoted context omitted.
All categories are arbitrary distinctions that someone made up at some point, including the categories of biological sex, race, and your birth name. At the very least it would be bullying behavior for me to single you out and call you a different name or different racial group to what you actually are (as defined by the constructs that society has agreed upon).
Biological sex is not a construct, it's a simple observable reality. Biological sex is factual and immutable.
Sex is an emergent property of multiple genetic networks. This doesn't mean that it doesn't exist or that it is not bi-modal, but it is far from simple.
https://www.nature.com/articles/518288a
The fact that we don't go around performing genetic testing on people before we interact with them also raises questions about whether sex itself matters, or whether there must be different definitions for sexed categories dependent on policy purpose. (e.g. based on genitals when the concern is sexual violence; based on fertility for the purposes of reproductive medicine; based on gender performance; based on hormone levels, etc.)