Let's imagine a con-man wanted to compete in women's sports. He would have to decide this early in life. Most trans people realize before they are 10. He would then have to spend the rest of his life pretending to be trans to not get his medal revoked.
Trans women are women. They don't have to pretend to be women. However, some trans women have to hide their identity and present as men, for their safety. Presenting as a gender you're not is incredibly taxing. There are high rates of depression and increased risk of suicide for people who have to hide their gender.
Besides the incredible psychological toll, our imaginary con-man would face bullying, harassment, physical assault, sexual violence, employment discrimination, housing discrimination, exclusion from healthcare, and increased risks of poverty and homelessness, which in turn correspond to greater risks of fatal violence.
The rights and legal status of transgender people vary by country. Our imaginary con-man might have restricted access to education, to sports, to bathrooms, and to marriage and military positions. As well as much, much worse.
On top of all that, our imaginary con-man would still have to train to be an Olympic athlete. Most men are not as fast or strong as the world's fastest and strongest women. Sex differences in athletic performance also depend on more than just biological differences. Living as a woman means only having access to the resources available to female athletes.
No man would go through all that for a women's medal.
Just because they are not male, does not mean that they are female.
dna never lies.
i.e., unless something fundamentally changes about how leagues are divided, there's going to be perceived unfairness in sports.
As long as things are unchanged, I think the real conversation boils down to who we prioritize: cis women or trans women.