
No one cares that some cis women have higher testosterone levels or are abnormally tall or whatever because the women's leagues were made for cis women to compete. Your participation is being accommodated and therefore you also have to be accommodating to any restrictions you may face that cis women don't, so long as they are scientifically based and not just plainly discriminatory
It's not useless to set a precedent for a scenario that is obviously increasing in prevalence. At one point, women didn't have jobs. You think when the first 5 women went to work at an office, they were just meant to piss on the floor because the company said "there's only 5 women, we don't need a women's bathroom that most people won't even use". It's a poor and useless argument. If you wanna see more trans people in sports, you can brush off conversations about making space for them to join