However the male feels, sports are segregated by sex (biology) not gender (social construct).
This.
Only one person can win a race so most girls have to accept that someone faster than them will win.
Yes. A girl faster than them.
If there are no rules, well, I can also take a horse to a 100 metre race for human males, be faster than them, and then say they had to have expected that there would be someone faster and I should get the gold medal and prize money.
They would not be amused.
Actually, they are already not amused if an actual human male who takes steroid is the one who is faster than them.
Rules. They exist for a reason.