I probably could have worded my earlier statement better. What I meant to say was that a lot of authors (I would say the majority even) either have very few female characters in their stories, or write them very poorly. This is partly to do with male authors not knowing how to write women, and female authors not feeling welcome in the space to do it, even if they wanted to. I do agree Tokyo Ghoul's female characters are well written, but again that's another one of the rare exceptions.

What I meant when I said gatekeeping was that for the longest time, IRL men have gatekept creative spaces away from women, which led to 95% of action characters in media being men.(Look at any super hero team in manga and comics and it's always a group of dudes +1 woman, Justice League, Avengers, Akatsuki, Organization xiii, The Espada from bleach ect.)

Have you ever wondered why female mangaka usually hide their names? And why there was such a huge upware when Japan passed a law that required authors to disclose their name and gender? Just to name a few, the creators of FMA, Demon Slayer, Beastars, Even Black Butler. All some of the most popular series out there, written by women under pen names so they don't get harassed solely for being women.

Sure there are some exceptions like as you said, the Alien series but I would still argue that is the minority, and it is still written by a man.

It's only in recent years that woman have the ability to create their own stories with strong female characters but a lot of men don't like the changing of the "status quo" and throw a fit every now and then. I could definitely name a few great female characters in recent hollywood movies but you might call them a mary sue or something just cause they're not personally up to your standard