Since men have been getting support and funding for over a century in sports and games like this, you end up with them dominating the field. Women's categories bring in more female players that otherwise wouldn't have a chance if the entire game was open only. But on the other hand, this enables concern-trolling over "transgender invasion". It's also applied questionably to sports that maybe don't need this such as in the case of Zhang Shan & Olympic skeet shooting. It can reinforce gender stereotypes. Finally, I'd say it's frustratingly slow at leveling the playing field.