High school sports don’t require any sort of hormones. Most sports don’t have official hormone-length schedules. But no, the advantage is not “negligible”. Height, limb length, joint size, heart and lung size, etc. are all fixed features. There minimal overlap between these aspects between men and women. A 5"10" person is average height for a male, but in the top range for females.

Longitudinal studies examining the effects of testosterone suppression on muscle mass and strength in transgender women consistently show very modest changes, where the loss of lean body mass, muscle area and strength typically amounts to approximately 5% after 12 months of treatment. Thus, the muscular advantage enjoyed by transgender women is only minimally reduced when testosterone is suppressed. Sports organizations should consider this evidence when reassessing current policies regarding participation of transgender women in the female category of sport. https://link.springer.com/article/10.1007/s40279-020-01389-3

And yes, certain “intersex” males should also not be competing in female sports.

because women’s sports aren’t sufficiently appreciated. Yep, the old argument: It doesn’t matter because women’s sports (i.e. women) aren’t important. The feelings of a ______ outrank the fairness in competition of a woman. Look at Veronica Ivy, who decided to take up cycling, dominated it, and casually turned to golf, and is now dominating it. So why isn’t Veronica Ivy choosing not to make all that money playing against men?

And as far as I see, women who don’t identify as women are still primarily choosing to play in women’s sports.