"Intersex" is a cultural concept humans have created based on DSDs. It's similar to the multiple concepts of "race" humans have created based on skin pigment, or indeed to terms like "priest", "slut" or "master" that are not based on any observed biological features at all, in that it is not a biologically meaningful term or an inherent quality of the human animal but nevertheless can still be a meaningful and consequential classification within human culture if enough humans believe in it.
To that degree yes "intersex" is or at least has the potential to be "real".
However, the potential cultural existence of "intersex" people does not negate the certain existence of just under half of humanity as simply and biologically female, and slightly more than half of humanity as simply and uncomplicatedly biological male. Nor does the potential cultural existence of "intersex" people remove the certain advantages that biologically male people, including those who may be culturally "intersex", have over female people in many sports, or the certain cultural and social disavantages and challenges that female people face in a society shaped by and for male.
So I always find it very telling when someone puts so much effort and concern behind the putative feelings of potentially culturally meaningful "intersex" people while glossing over the documented, ongoing and undeniable injustices faced by female people. It's almost like caring about a vast everyday injustice faced by half of humanity is too mundane; their special and refined sentiments are only moved by rarified and special injustices.
Now, I am happy to hold my hand up and say I don't watch sport of any sort. I find women's, and indeed men's, sport mostly very tedious.
Nevertheless, I very much care that the women who compete in women's sports get a fair go and that their sports are valued and respected for women. Not because I give a shit about sports especially, but because I very much do give a shit about women.