A strong case can be made because the line is extremely blurry and there can be severe consequences for forcing a category on people that doesn't fit. Sex and

A strong case can be made because the line is extremely blurry and there can be severe consequences for forcing a category on people that doesn't fit. Sex and gender are shoved in people's faces practically every waking moment which means this "highly accurate approximation" breaks down billions of times a day with consequences ranging from discrimination and depression to sterilization and death. How certain are you that you or some close doesn't fall outside the binary?