sports just aren't that interesting. It negates all the mental and emotional aspects of competition that people enjoy.
This goes for transgender athletes too. Medications and surgeries can partially level the playing field, but not entirely. Any time a transgender athlete wins, the assumption by most people will be that the victory is attributable to some unfair advantage that wasn't fully mitigated.
No one wants to watch an F1 race car go up against a Honda Accord, not even the drivers.