I think most of us would probably agree that there are different rules for women in society generally. It's not really a new idea. And that's one of the reasons the waters around this were muddied in the first place.
It should never have got this far.
Women should have been respected enough in the first place that our voices were just listened to when we said it wasn't what we wanted. Then there wouldn't be so much angst now about where TW are going to pee when out in public because third unisex places that anyone (trans or not) could use would already have been established and that would have been the norm that everyone accepted. It would be well established now and everyone would have been respected. Job done.
You are absolutely right that lesbians were of little interest to law makers because no one really took much notice of women and what they did generally. The biggest problem that lesbains pose to men is that they won't have sex with them. But it's OK, because they managed to turn them into sexual fantasy - so phew! Some use after all!
So gender non conforming women are less of an issue because they pose absolutely zero threat to men in any capacity. Some men find androgynous women, androgynous presenting women, women in masculine clothing sexy. Well that's OK then! As long as men's sexual interests are still catered.for, it's all good! The only reason women had to fight to be allowed to wear trousers and flat shoes in the workplace is because men find women in short/tight skirts and heels sexy. So that was what women were required to wear regardless of how uncomfortable, impractical, physically damaging or painful those clothes/shoes were.
A lot of societal rules are based around the idea that a woman's primary function was/is to be sexually appealing to men at best and unproblematic at least. And women standing up and saying no to men is breaking the social contract that men applied and no woman explicitly agreed to.
It makes the majority of women uncomfortable to feel like that. Some respond by modifying their appearance to appeal to male sexual desires. Some respond by hating their 'inadequate' bodies. Some will respond by removing their 'femininity' and womanliness by transitioning to take themselves away from the male gaze. Some will just try to avoid men like that and hope they've found themselves a good one. Some will reject it all as nonsense.
It is different for transmen because they pose absolutely no threat to men whatsoever. They never claim to be 'more of a man than you'll ever be' because they're not in competition with men. Most I've spoken to/read about are just happy to be in their acceptable, unremarkable new 'male' body, to not be bullied anymore for not being feminine or pretty enough to avoid male crticism or subjected to lewd remarks because they had the temerity to grow breasts at 12.
Primogeniture laws weren't changed so no man will ever have to worry about a transman taking what's rightfully his away from him. And men have been permitted to exclude transmen from their spaces on the basis they weren't actually male. Eg the gay sauna that said they wouldn't accept a transman because they were gay and only attracted to other men and the transman was a woman. Where was the same, "Well, yeah, that's obvious!" when TW were.getting women kicked off lesbian dating apps for saying the same?
And most men could still beat up a transman in a fight or win over them in sport. So no threat there either.
A transman won't win business awards or other accolades designed for men because they weren't real or born men so why would they? And men 'feel' this.
So everyone knows and always knew that transmen were really women underneath the newly acquired muscles and beard. Men had no fear of being raped by transmen because a) women don't generally go around sexually assaulting people and b) men generally don't go around worried about being raped by other men anyway.
Basically, no one was under pressure to prove they believed transmen were really men. More than that, they were allowed to not believe it. And until this was pointed out, transmen were largely ignored by the trans rights movement. If the rules/expectations had been applied consistently across the board, i might have accepted that some people really did believe you could be born in the wrong body. But they weren't because they didn't. Otherwise, how would the eldest daughter not become the eldest son for inheritance purposes? It was because, deep down, everyone knew the truth, and that was a male privilege.
So transmen pose no threat to men on a societal, sexual, financial, sporting, dignity, professional level in any way.
And I don't think I need to make this post any longer by explaining why transwen are different because its all been said a million times already.