Even if it were scientifically established that hormone therapy in transition from male to female after male puberty negated any advantage that trans-women have over cis-women, which it isn't, the Olympics' rules still don't make sense.
The Olympics allow trans-women to compete so long as their testosterone is under ten nanomoles per liter of blood. What is regarded as a normal, healthy amount of testosterone for cis-women is 0.5 to 2.4 nanomoles per liter. So, trans-women are still being allowed to compete with cis-women if they have four times the amount of testosterone of the highest level of testosterone that's regarded as normal for a cis-women.
If during the last Summer Olympics a cis-woman athlete had been discovered to have been taking testosterone as a performance enhancer while maintaining levels of - say - 8 nanomoles per liter, would anybody seriously not view her as a cheater?
Over the course of too many years of me talking about this issue, it's become clear that the opposition isn't just ignorant of what doesn't change during transition - they're basically demanding to remain ignorant.
Yes, taking estrogen reduces muscle mass and increases body fat. A trans-woman would be at a disadvantage competeing against men. That doesn't change the composition of the muscle fibers. Men have more fast-twitch muscle fibers. Reducing the mass doesn't change the composition. Trans-women with the same muscle mass as cis-women will still have an advantage in explosive athletic competition.
"Transphobe!"
Estrogen is actually commonly used in treatment for osteoporosis. Men already have better bone density than women. Especially in impact sports, that's an advantage.
"Transphobe!"
Estrogen doesn't change the size of your heart and lungs.
"Transphobe!"
Okay, distance running is mostly reliant on slow twitch muscles and hemoglobin. In that case, there's little evidence that trans-women have a significant advantage.
"Still a transphobe!"
Fallon Fox inflicted skull fractures on cis-women.
"Transphobe! Also, Fallon Fox lost one match to a cis-woman. Trans-women don't always win."
Yeah, Fallon Fox sucked in terms of technique and relied on brute force. Trans-weightlifters have been rising from ranks around 300 in male competition to top three - if not shattering records after transitioning to women's competition.
"Transphobe!"
There's a reason why the Olympics have no restrictions on trans-men competing with cis-men.
"Transphobe!"