"Even questioning why we use different pronouns for people based on our assessment of their sex/gender"

I've always taken this to just be about ease of identification. If I'm talking about somebody whose name I don't know, I'll refer to them by their gendered pronoun. If that doesn't whittle it down enough, I'll use other things like their height or the colour of their skin or what they were wearing. Also, even if I do know their name, it's clunky to refer to them by name at all times so he/she is easier on the ear.

I find the politicisation of pronouns so strange! They're such a benign, purely descriptive part of speech as far as I'm concerned.