I don't mind the default, but it's the lack of customization in most apps that is a severe oversight. I can't change my theme in the OS without it telling apps I want a dark theme (I don't). I can't change the theme in the browser with it telling every website I want a dark theme (I don't). There are no overrides to force the website rendering theme to be decoupled from the browser/OS theme. In everyone's mad dash to implement a dark theme, no one stopped to think for half a second. It's asinine.