I was clumsily posing that gender is lived, not determined, and influences how we are treated and who we become.
I think you are confused about gender too. Here is the definition of gender from the WHO:
Gender refers to the roles, behaviours, activities, attributes and opportunities that any society considers appropriate for girls and boys, and women and men. Gender interacts with, but is different from, the binary categories of biological sex.
Gender is what society considers appropriate. It is defined by other people's expectations. Women and men are limited by gender expectations regardless of how they actually behave and regardless of their own personal sense of identity. 'Gender' is the thing that prevents a man from wearing a skirt in the UK, unless it's specifically a kilt.
Conversely, while it has been socially acceptable for decades for a woman to wear clothes that are entirely 'male', this does not allow women to escape gender expectations, and they still need sex based rights.
But everyone’s biology is also unique, and there are as many differences between people with the same biology and similarities between people with different biology, to say that there is more going on, and that biology (sex, genetics, race, ability) is as relevant as society makes it.
I'm not sure how you are viewing this site, but look at the top of the page - can you see the menus for conception and pregnancy? My personality, views and interests might be more similar to 90% of men than to 90% of women, but I cannot escape the consequences of a female reproductive system. I need sex based rights. How is this so difficult for you to grasp?
I don’t know if it is possible to live an authentic life as a woman (or as a man) - but I hope it’s something to strive for?
Why not just live an authentic life as a human being?
Perhaps an analogy might help you. Somebody with hearing loss may suffer direct discrimination, and they may suffer indirect discrimination because e.g. at the moment they find communication difficult because people are wearing masks.
None of this has anything to do with their identity, validity, value or authenticity.
If you are really interested in this subject, you should read 'Invisible Women' by Caroline Criado Perez. It is study of all the ways that women suffer indirect discrimination, because it is assumed that sex is irrelevant.