This is a data driven discussion being hijacked by people for their own reasons.
Data driven?
Here's some data:
A child changing gender neither picks America's pocket not breaks America's bones. What rationale can the state put forth preventing someone from performing an action which causes no injury to anyone?
Seat belts. Helmets. Illicit substances. Firearms. Increasingly, food and/or ingredients. Property uses. Construction codes...
Seat belts and helmets demonstrably save lives, so there's a public good to be realized there. However even that is not universal, many states let you ride without a helmet and I kinda don't see the problem there, do you?
Illicit substances are a holdover from Prohibition, but do also harm others; that's why we're at war with Venezuela. Applied to food that's why we have the FDA. Spoiled food harms others.
Firearms are only a right because of a legal peculiarity. Any data driven discussion of firearms would quickly determine a legitimate basis for regulation, as seen in every other modern country.
All of your examples, except seat belts, are examples where government is protecting unsuspecting individuals and innocent bystanders from harm. As for scope, about 100% of us will ride in a car at some point, most of us will be in a car crash at some point. Unlike changing genders which applies to a very small few.
That's not the case with changing your gender. There's no third party the State can advocate they are protecting here.
And guns is a great example. Far more suicides by gun than other method, but we don't effectively regulate that. So why regulate the far fewer number of people who want to transition?
What is the state's justification for seizing that liberty and denying that freedom?
It's okay if your answer is "I don't know" because that's my answer too.
I'd like a good data driven narrative to curtail freedom, before curtailing it. Like I did with seat belts and stuff.