Agreed, but trying to fix societal problems by misrepresenting biology (or any other science) is foolishness. Reality has a very unpleasant habit of making itself known whether you want it to or not.

So it's not a good idea to promote ideas like "if science expects to be objective, 'sex' is a useless concept".

One way or another, society is going to have to accept that (1) sex is a useful, well-defined scientific concept, (2) there are rare cases where sexual dimorphism is absent or isn't expressed in the most common way, and (3) a compassionate society that fulfills the needs of all of its members is going to have to grapple with (2) without denying (1).