whereas transitioning transperople seldom benefit socially/economically
This may have been true at some point (when people who saw themselves as transsexual were targetted usually by people who assumed they were gay or lesbian - so, because of homophobia) but it isn't true now.
Among wide swathes of young people, being trans is a high-status position. Among adults, there are plenty of high-profile trans people who wouldn't be given the time of day, never mind a platform, if they weren't trans. (If you ask me for a list I will supply one.)
All the major political parties, including the party in government, are prioritising trans rights over other rights. When you have both the government and almost all parties in opposition on your side, it's difficult to claim you are disadvantaged.
Many organisation, including organisations aimed at providing services for young people (eg the Guides), have active policies aimed at protecting the rights and privacy of trans people, but have repeatedly dismissed any calls for the same rights and privacies to be offered to the girls and women who use their services.
If you look at the "top earning women" in some sectors of industry, they aren't top-earning women at all - they are men. Genderfluid men who spend some or all of their time at work dressing and presenting as the men they are, and only occasionally wearing "women's clothing" (not that I believe there's such a thing as women's clothing - it's all just clothing) get speaking slots in Women In Industry events, get approving profiles done of them in the financial press, etc etc.
Mediocre male sportsmen who then identify as women are winning women's events with their larger, stronger physiques, when they never were able to win men's events.
tl;dr there's a lot of evidence to suggest that plenty of trans people benefit both socially and economically from their transition, often at the expense of women.