Trans women who have been on hormone therapy for at least a year have no overall advantage over cis women in most real, existing competitive sports. They have disadvantages in some of the most widely-sports-relevant capacities—compared to cis women—and small advantages in a couple of isolated abilities (grip strength).

They also have advantages in traits that across the population correlate positively with some broadly-sports-relevant capacities (e.g., lean body mass, both absolutely and as a share of total body mass, lung volume), but the actual sports-relevant capacities these correlate with on a population level (strength, endurance, etc.) they don't have an advantage on. There are studies that have detailed some of the low-level reasons for this with regard to oxygen use and other factors.