That's a different treatment though, because puberty eventually resumes. Halting it entirely is more akin to the castrati children [1] who had their puberty physically blocked through removal of testicles.
[1] https://www.mayoclinic.org/diseases-conditions/gender-dyspho...
Also, I do not think medical sources from America are reliable for this topic. The UK and the EU have moved away from gender-affirming care and designated it an experimental treatment. Medical and psychological associations in the US have been captured by such activists and are pushing false rhetoric such as "the science is settled" and "we have medical consensus" (note the misrepresentation here; consensus does not imply evidence-based).
US have a problem where radical activists have captured many influential cultural institutions. Anyone who disagree is automatically designated a "right-winger", "conservative", "white supremacist", "oppressor", "racist", "sexist", "homophobe", "transphobe", etc. This should be obvious to anyone looking from outside the anglo-sphere. For things to get to the point where US can't even recognise what a medical scandal is is frankly appalling, especially when their counterparts in Europe is able to do so.
[0] https://whyevolutionistrue.com/2022/11/15/nyt-questions-pube...
The UK and EU are hardly a paradise for trans people. Until recently they even REQUIRED trans people to be sterilized, I suppose under the dual assumptions that 1.) they weren't fit to have children and 2.) if there's a genetic component to being transgender it's best to weed it out.
https://www.nytimes.com/2017/04/12/world/europe/european-cou... (this was only stricken down in 2013)
These days, you'll notice a lot of europeans calling to clamp down on transgender people because they'd prefer for them to be gay. Conversion therapy is conversion therapy, however, and whether you do it US style where you try to make someone a good straight Christian or European style where you try to make them a feminine male or butch female, it's still wrong.
As for sterilization, people bring this up without pointing out that we can bank sperm and eggs. A treatment plan for trans youth can wait until they reach a tanner stage (these are the stages of puberty) where they can bank before starting puberty blockers. That is more reasonable than an outright ban.
As for Lupron's side effects, parents are informed about possible side effects. Just like with precocious puberty. It remains telling that families are allowed to access these treatments for some reasons but not others. The double standard betrays prejudice and political meddling in the affairs of parents and doctors.
[0] https://www.bmj.com/content/380/bmj.p382
[1] https://www.bmj.com/content/380/bmj.p382/rapid-responses