Re: Is this just an English thing ?
Uncomfortable with the body you were born with describes every teenager ever.
As does confusion and the desire to experiment with gender identity and sexuality.
The bit that is a fad, specific to the late 2010's is the bit about inventing your own "gender", and pronouns, and the desire to attack and outlaw anyone who fails to use them.
When I was young there were different fads which look equally bizarre to not anyone of that specific age of that specific time.