The Olympics have allowed trans women to compete against cis women since the 90s, and yet there’s never been a trans medalist. If there was a genuine advantage to being trans in sport, at least one country in the past three decades would have loaded their team with trans women and cleaned house. However, taking enough hormones to make a masculine body into a feminine one after it’s already grown means you’ve got way less testosterone than a cis woman, so that counters out any initial advantage. Claiming otherwise is misinformation. Spreading misinformation to the detriment of trans people is transphobic.