Though I agree with you that development is messy. We should be much more concerned about exposing children to endocrine disruptors, micro-plastics, and bizarre social dogmas.
It's been a rather contentious topic, and sciam has even written about some of the issues: https://www.scientificamerican.com/article/evidence-undermin... ( https://archive.ph/N1nAR )
"The American Psychological Association and 61 other health care providers’ organizations signed a letter in 2021 denouncing the validity of rapid-onset gender dysphoria (ROGD) as a clinical diagnosis" -> https://www.caaps.co/rogd-statement
For example, recognition of the existence of the syndrome and reduction in social stigma. Kind of like how the rate of homosexuality increases when you stop subjecting them to vivisection.
By comparison there's been a 40-50x increase in gender clinic patients in just 11 years from ~100 patients in 2011 to 5000 patients in 2022: https://segm.org/images/280UK_22.svg
The point here is that if there's discrimination against certain characteristics, there will be individuals that will deny part of their identity to the outside world.
So whatever is causing trans identification to increase ~250x faster than left-handedness is happening despite increasing discrimination against trans individuals.
Actual discrimination would be things like, repealing laws that protect individuals with a trans identity from being refused housing or employment because of that identity (or expression thereof). As far as I know, no-one is pushing any bills that would do this.