Sex not being binary is technically correct, the best kind of correct, but it misses the wood for the trees.

Most (but not every) step on that continuum are known as diseases of sexual development [0].

These arguments often come up in discussions around trans issues, but its a trick of misdirection, although the DSD community does have a higher incident of gender identity issues (which is what you'd expect), around 5%, 1% that actively changed their gender, the lack of transition within the DSD community seems to suggest DSD and gender dysphoria are not related phenomenon.

The idea that sex is a continuum, based on known disorders, is like saying human bipedalism is a continuum due to people being born with less than 2 full legs, or more than 2 legs (extra toes), or losing them in later life. Although technically correct the observation does not really change the conversation.

[0] https://en.wikipedia.org/wiki/Disorders_of_sex_development

[1] https://pubmed.ncbi.nlm.nih.gov/29606626/

[edited for clarity] added: the lack of transition within the DSD community