Ridiculous. You can’t say that intersex is common. It’s extremely rare. You can’t use intersex people as an example to obviate the biological duality of sex, which upon all generation is based since all of human history.

Intersex is a biological anomaly and can’t be used to invalidate the concept of sex as a generality. Even further, most intersex people still manifest as either male or female.

The idea that intersex people exist doesn’t invalidate the idea that there is a male and a female.

So without being daft, you tell me which category of sex they’re talking about.