Who or what bears primary responsibility for transgenderism?

This extremely lengthy (beaucoup comparisons and analogies) but highly intelligent essay on transgenderism

https://open.substack.com/pub/artymorty/p/the-power-of-the-powerful-blame-the

contains the following question:

"How did something as self-evidently bonkers as trans ideology 

gain such a powerful grip over our society? 

Over our politics, our universities, the [media] and countless other institutions?"

There are of course several answers to that question, but I think a considerable part of the responsibility lies with 

the medical associations who have promoted "transgender health care" as being a "medical necessity."

(Also the American Psychological Association 

https://www.apa.org/news/press/releases/2024/02/policy-supporting-transgender-nonbinary .)

Once the professional associations do that, many of the other pathologies we see in other institutions fall into place.

Who can argue with medical associations over what is "medically necessary", 

or the APA over what mental illness is or is not?

It would be interesting to see an examination of 

how the medical associations in particular came to such full-throated endorsement of one side 

on what is obviously a controversial, socially divisive, and politically charged issue.