I transitioned before I was 18 and it was 100x the correct decision for me but I do think, they should look at case by case because people can have permanent body alterations from taking hormones. I would say though 80% of the time it's the correct decision for that individual.
My understanding is that, without transition, most desist and become comfortable with their bodies again, so the rush to transition kids is not empirically justified in terms of care.
We should be questioning why so many children are uncomfortable with their bodies these days. Honestly, I've heard of girls claiming to be trans because they don't like their periods or how their breasts are sexualized... but those are both normal of girls that age.
