massive correlation with being trans, and being super adhd/asd/french/some other mental disorder (having one disorder means you have a strong possibility of having others, they're all extremely tied into each other, including gender dysphoria) which are things that cause you to be significantly more likely to spend a majority of your time on the internet and on obscure/nerdy/highly derived forums for various complicated and straightforward reasons.

being a social outcast also may push people towards corners of the internet, and trans people are often social outcasts even if they don't have some other disability causing them to be (especially those from more rural/more conservative or religious areas)

Plenty of trans folks go harder on gender expression online because they have difficulties to do so IRL, even if being female presenting tends to result in more issues.