I don't think your example is a good one for proving your point. If a bunch of politicians from Australia and wherever you live got together and signed a few papers, your neighborhood could become part of Australia, and then you would be Australian. Nationality isn’t determined by “objective reality “ whatever that is. You are either Australian or not because certain people say you are. So who are the certain people who get to decide what gender you are? Gender is not a political category, so there is no reason to give the final say to politicians. Consequently, if we stick with this analogy, there’s no reason for it not to be a matter of personal choice.
If you had chosen another category, such as a biological one, you might have had a somewhat more plausible case, but only somewhat. Modern biology, unlike Aristotelian biology, doesn’t divide living things into neat categories. According to Darwin all of us, from elephants to potatoes, are descended from the same mitochondrial Eve. If differences between species are blurry, there is no reason to have sharp lines separating other biological categories, such as predator/prey, animal/vegetable, or male/female.
Of course, all these arguments work equally effectively against the Trans people and their allies who keep chanting the mantra “Transwomen. Are. Women. Period. ”
However, Putting. Periods. After. Each. Word. Does. Not. Make. You. Right. Neither side of this debate has much argument to back up their conflicting assertions, so the “argument” really becomes little more than a shouting match. If you want to join this shouting match , you can go over to my posting of this article on my Daily Kos page, and shout away. https://www.dailykos.com/stories/2021/6/26/2037201/-The-inescapable-dilemma-of-trans-women-in-sports
The real objective facts of the case, as I seem them, are 1) transpeople really really need to make these changes, or they will undergo unbearable suffering and 2) because biological categories are inherently blurry, there is no objective reason not to give them what they want. However, including Transwomen under the category of women does radically change the original concept of what it means to be a woman. That’s not a bad thing, but we have to be open to all the implications of these changes. One of the implications could be a change in an imbalance of sports abilities that was once classifiable as a man/woman distinction. With this new definition of womanhood, it seems plausible that many of these abilities that give cismen an advantage over ciswomen would also be possessed by transwomen. There is a complicated set of tests, involving mostly testosterone levels, that are designed to exclude transwomen that possess those advantages. There is apparently evidence that these tests have worked, because Transwomen arguably do not do significantly better at sports than ciswomen. But because these tests exclude many transwomen, and some ciswomen as well, it might be better to call them something other than male/female differences. I expand on this on one of my other comments on this page.
