When talking about the “sex vs gender” debate, you should 100% trust an evolutionary biologist more than a gender studies scholar on the “sex” part of that debate. I’m not sure why you think that’s unclear.

gametes are a binary

Thank you, you’re the first person in this thread that I’ve been arguing with to acknowledge that. Sports and whatnot are a different topic that is interesting to talk about, but first we have to get everyone on the same page of acknowledging the scientific consensus here that sex is binary and entirely defined by gamete size. Then we can start talking about how it affects sports.