That's a dangerous thought process. Silencing people who don't understand things surely cannot be good as a whole.
Stress reproductive role there - as unique individuals they have limitless other personal and social roles they can fulfil, and to be honest I don’t see these as naturally gendered, nor feel it would be desirable for it to be so.
As someone born in the 60s, a time when gendered roles began to be considered limiting and harmful, I would genuinely love to see a defence - at least one beyond “It makes people with gender dysphoria happy” (which is a good thing, but not obviously the right thing given the opportunity for discrimination between genders and expected conformity to normative gender stereotypes).
As Wright notes in https://www.realityslaststand.com/p/sex-is-not-a-spectrum, this view of sex as a binary system is based on the concept of male and female being the two discrete halves of the reproductive system in humans (and other anisogamous species):
"Biological sex [...] is connected to the distinct type of gametes (sex cells) that an organism produces. As a broad concept, males are the sex that produce small gametes (sperm) and females produce large gametes (ova). There are no intermediate gametes, which is why there is no spectrum of sex. Biological sex in humans is a binary system."
Surely this is not an unreasonable starting point for an evolutionary biologist to extrapolate from?
Saying sex is a binary is excluding anyone that doesn't fit within that binary. And if that's something you can't imagine, then it's not a subject you should have or voice an opinion on.