I think there's a large degree of "this question is not nearly as important to me as it is to society" here. It's very important to have an explanation for why you, a man, want to portray a woman in a fictional context up here in our culture.
But i don't really care about that. That's something other people care about a lot. I just made up this cool lady in my head and want to go be her while i murder things for a while.
I think there might also be some "the only way to not portray a toxic masculinity manchild in a lot of games is be a woman or an alien" , too. Like most shooters are made for a statistically average 24 year old American man and I am extremely not that and often find almost any other character more relatable than dudebro mc doodbroson.
I wonder if there isn't an element of "if i'm portraying a woman i can also, for once, take off the cloak of fear and violence that i must otherwise carry around as a man in this society" thing going on. Cause that cloak is really fucking heavy. I don't like wearing it. And sometimes in fictional spaces, by portraying a woman (or, in one notable case, a genderless pile of greasy rags with a katana sticking out of it that would sometimes do extreme violence :kenshi-ninja: on behalf of their friends) not so much bc i want to be a woman, but bc in that moment i want to escape from the weight and terror of being a man in our society. Idk gonna have to think about it. Bc what if the gender expression you dislike isn't the internal self-conception, butt he horrible social, political, and economic realities that come with being assigned that gender? Like I don't have strong feelings about being a man, but it is very definitely what "fits". But i have very big feelings about being an American man and a white man and a straight man and a bunch of other kinds of man in this specific violent and awful culture, and i'm thinking that sometimes being not-a-man is a way to escape that burden of cultural horror, rather than a desire to not be a man. Damn, that sounds smart, i'ma have to work on that, i've been trying to figure out how to express that for a long time. I don't want to be a man, not bc i want to be something else, but bc being a man in this society makes your a person who harms other people, even when you don't mean to or are actively trying not to, and i don't want that part, but there's no way to get rid of just that part in this society at this time.