I would just point out a couple things.
1) Gender affirming care is a much broader set of interventions beyond permanent physical changes. Do you "100% agree" with banning all gender affirming care, or is your concern with the more permanent surgeries and other physiological treatments?
2) We do let kids mutilate their bodies all the time. Some examples:
* Ear piercing
* Haircuts
* I think tattoos are allowed with parental permission
* Roughly 2,398 medical surgeries and procedures done regularly on children (I made up that number but it's a lot).
If you're saying we should think hard before allowing our children to undergo permanent (or difficult to reverse) physical changes, then I agree! I think everybody does. So if that's what you're getting at I think it's fair but it doesn't really provide a defense of or reasoning for the original position.