Years ago I remember hearing about the subreddit r/actuallesbians. Some trans people were afraid that with a name like that it might be TERFy. It wasn't; it was inclusive (at least back then - I don't know about now). It was called "actual lesbians" because r/lesbians was not about lesbians as people, but about lesbians as a porn category.

Lesbians are the single group most likely to support trans people, with a massive 96% of lesbians under 25 in the UK being supportive, and it's not hard to see why.

The poll that found that figure suggested that lesbians are more likely to personally know a trans person, which may be part of the story, but more so I think it is a natural alliance because both lesbians and trans people are groups of real people that the patriarchy insists on reducing to porn categories.

Because as porn (or more specifically porn for the male gaze) is the only way both groups don't threaten patriarchy. It is how patriarchy contends with something Not For Them.