People with XXY chromosome are a special case. Men (XY chromosome) who identify as women (XX chromosome) are men. How long before all women’s world records are held by XY chromosome women (sic)? There is more male advantage that testosterone in the male anatomy.
So I agree, we cannot define sex by testosterone, it is defined by the Y chromosome. We need to stop destroying a lifetime of training for female athletes to accommodate men who wish to compete as women.