Not sure if the mods will build it (I'd say unlikely -- nothing has changed in the decade I've been here) but in the meantime, you could use a CSS browser plugin and edit the CSS yourself
Back in the day, all BBS's were dark mode.<p>Then the web went bright around Web 2.0.<p>I also would like dark mode, but by default and not requiring a login with preferences.
You can install Stylus in your browser and use one of several dark themes, or make your own.<p><a href="https://userstyles.org/styles/113994/hacker-news-dark" rel="nofollow">https://userstyles.org/styles/113994/hacker-news-dark</a><p>With the structure of HN, it doesn't take a lot to make something nice.