Humans have more than 2 sexes. Sex is a convenient category based around a phenotype, not a golden rule that all organisms adhere to. People who exist outside those phenotypes are not defective or malformed and do not necessarily require surgeries to ‘correct’ their bodies and make them fall in line with binary sex categories.

By asserting sex as binary and immutable you are actually doing the legwork of transphobia for transphobes. They also assert that sex is binary and immutable. They deny that anything such thing as gender identity or expression exists in the first place, instead asserting that gendered behavior is a direct product of biology.