Puberty is not a disease and "needing" the treatment sounds too strong a term.
We all go through tough things in puberty and no treatment is going to make a male into a female or a female into a male, whether it is started earlier or later.
Let's do a thought experiment.
Imagine, you're an adult man, you identify as male, you have a penis, you are reasonably fit and you are currently trying to grow a beard because you like the style.
Then, one day, you notice that the beard is not growing, your facial hair is very sparse. Also, your penis seems to be shrinking and your chest is puffing up... Not with muscle, though... You're growing breasts.
You go to the doctor. The doctor explains to you not to worry. This is not a disease, it's a natural hormonal change. She could feed you hormone blockers or even testosterone to stop and reverse these changes... But that would be a serious medical procedure.
Instead, why don't you talk to a therapist about accepting your biological body as it is? If you still feel uncomfortable with your breasts and small penis in two or three years, we can talk about hormone therapy. The breasts may need to be surgically removed if we wait, but still: let them develop first, maybe you will come to your senses and understand that there's nothing wrong with your biology.
That is what you're suggesting to put trans teens through, if you argue for strict age limits an no intervention during puberty.