Trans people have been able to compete at the Olympics since the mid nineties, so if male puberty really did have such a large effect on performance, we'd have had next to no cis women win medals for three decades. Instead, every women's Olympic medal in that period went to a cis woman. Taking enough hormones to physically change the shape of your body has a detrimental enough effect on athletic performance to wipe out the advantage from male puberty. In principle, an athlete could gain the advantage back by stopping taking HRT, but the Olympic rules require stable hormone levels for two years, so they'd just disqualify themselves if they tried.