A trait I share with dictionary editors is a preference for linguistic descriptivism, so for me it's not a real problem that the common definition of "sex" and the scientific use are different.

Unfortunately, reality doesn't care at all about the categories humans create, so there's always some exception like the following two no matter how you try to cut reality at the joints with word definitions.

Even in humans, we see all kinds of interesting things going on. No reason to think this would be limited to downstairs and not in our brains, assuming there even are any differences between male and female brains (which is unclear to me, given vitamins and cortisol and how much sleep we get all impact our brains): https://en.wikipedia.org/wiki/Ovotesticular_syndrome#Fertili...

Beyond us, but in the same general category, biologists collectively chose to define "sex" in sexually reproducing creatures such that the one with the smaller gamete is male.

To illustrate how arbitrary this is: seahorses. The sex which gets pregnant has the smaller gamete, i.e. males get pregnant.