There is a weird appeal to authority randomly added at the end of the article. Just because someone with a PhD has an idea on what may be good for users doesn't prove it actually is. Such a decision should be grounded in user studies and telemetry.

Having a light mode and a dark mode as the target of the setting, makes it impossible to use a light area versus a dark area to meaningfully suggest visually which one is selected. This stymies the designer completely, apparently.

I read this up until the monospaced use of the term `localStorage`, which for me (Firefox on Android) got rendered with a white background but did not invert the font, making it unreadable without highlighting it. I don't think I'm interested in someone's take on light versus dark theme if they don't seem to actually know how to make their own website work right with dark theme.

If the site defaults to system (which isn't guaranteed), very few people will need the toggle, at which point it can be omitted, or at least hidden deep in settings, and there is no need to put so much thought into its design.