To me sports is really going to be on the forefront of these discussions, because it's one area in modern life where it's the physical that really matters--your muscles, your hormones, etc.. And, there are objective winners (and losers)--the fastest time, the biggest lift, the most points, etc..
Something like acting is just totally different. Brad Pitt could submit himself in the Best Actress category if he wanted, but there would be a big outcry about it, and probably no one would vote to nominate him there in the final grouping, or vote for him to win that category if nominated. The nominees and winners are very subjective, a collective anonymous decision. But you could have a transgender actor, who is completely biologically male still but identifies and lives and works as a woman, submit themselves in the Best Actress category, and no one would claim they have some kind of "unfair advantage" due to being biologically male. It's about acting skill (and let's face it, lots of other things like politics and campaigning and box office returns and how good the rest of the movie is) not hormones or chromosomes.
In the case of the track athletes, if they have been living as teenage girls--in dress, manner, names, etc.--it does seem weird to me, to make them compete with the boys. On the other hand, if they have not started any medical intervention, then they ARE boys physically still, and have some physical advantage over the girls running next to them. But then you have the idea that they want to be athletes, and they also want to be girls, they are not "boys in dresses and wigs" pretending to be girls for the physical advantage like in some bad sports movies I saw in the '80s. Do they have to give up on being one or the other--athletes or girls--for the time being? They may have an advantage in this particular race, but they don't necessarily have an advantage in LIFE as a whole, they are facing a lot of obstacles that the girls they run against don't.
I have no idea what the answer is, although I like the idea of dividing people up based on hormone levels or muscle mass or something like that, not sex/gender. I'm sure for most of human history, dividing by sex/gender seemed like an obvious, reasonable, objective idea. But now we understand better that it's not always clear.