That's your framing. Nobody wants to see men competing against women in sports, and it rarely happens anyway. You guys see trans-hulk athletes everywhere you look, or you think you do. We see a tiny number of kids who deserve the same rights and opportunities as all the other kids, and that includes participating in HS sports if they so choose.
As for kids getting treatment, Dems think that parents and doctors should be making those decisions, while you think that the government should make those decisions. Your "age of consent" argument is crap, though. Does that also apply to cochlear implants? Glasses? Vaccinations? Or does it just apply to those procedures that you, with your zero expertise, consider icky?
Like most conservative positions on wedge issues, ignorance is the basis of your beliefs. You are ignorant of the tiny number of trans athletes, you are ignorant of their tiny effects on HS sports (both negative and positive), and you are ignorant of what is in the minds and the pants of kids who may very well benefit from treatment, not all of which is surgical.
There is a significant number of kids who don't fall into the two rigid traditional gender categories. There always has been. And nobody is more aware of it than the kids themselves. It's their issue to deal with, not yours, and not the government's. Your position is far closer to that of some countries we consider backwards, where homosexuality is still illegal and women are routinely mutilated.
Finally, you have defined "far left" by wedge issues created by your Republican politicians, and not by "far left" policy issues, like universal healthcare and support for organized labor. Congratulations, you have been duped for your vote.