Drug use. This one might be more flawed, but for the most part how many druggies do you know suffer from all the diseases related to drug use after merely doing drugs for two years? Because even then, I feel like the average struggle for far longer before having any major illnesses.
Loads of people even pick up a relatively “mild” heroin addiction for years, before they suffer any real problems.
A better comparison would be smoking.
There are people who briefly smoked, gave up, but developed lung cancer anyway.
Maybe puberty blockers don’t show much difference in a relative short term, but there are the invisible undetected effects and risks.
I vaguely recall someone claiming on this forum that even the kids who suffer precocious puberty are put on the blockers with reluctance and monitored and taken off them as soon as its appropriate.
Going to have to do some digging but I quite vividly recall a 90s documentary on UK Channel 4 about two children, boy and girl, who suffered precocious puberty.
The boy understood that while he was a tall boy (5-7 years of age and already over 5 feet) he would be a short man. I forget the specific reason, but it was related to the blockers.
The issues that the children suffered was the girl starting periods at 5, and having the stresses of early puberty nearly 8-10 years too soon, yet the boy was considered a risk to his peer group.
He was obviously larger than other children his age, was already developing adult muscles and could match 14-16 year old boys in strength, and had to be taught appropriate times to masturbate.
The parents, teachers, other responsible adults were also concerned for if he became interested sexually in his female classmates.
Not that they thought he was a young paedophile, more that teenage boys usually develop crushes on their immediate peer groups first of all. Girls tend to attach to unobtainable men like pop and movie stars, but boys initially fancy girls they know.