Environmental lighting conditions rule the day! I have astigmatism and I prefer bright backgrounds; #000 text on #fff backgrounds works great for me, but that's because I work in a room lit by a 250W 30,000 lumen corn-cob LED bulb[0] that makes my small office as bright on the inside as the shaded ground from a tree on an overcast day (which is quite bright compared to usual indoor lighting). In a room that bright, high contrast text works great and is highly readable, with "dark mode" often looking washed out and muddy. Even small reductions in contrast (such as what https://devdocs.io does with text of #333 in light mode) can make me notice and wish for greater contrast.

[0] - https://www.benkuhn.net/lux/

I agree, users should be able to pick whatever works better for them.

There's a myth going on that dark mode is universally/objectively better which is simply false.

I too have astigmatism and am a light mode enjoyer. Dark mode makes the letters dance in front of my eyes.

Display brightness at 20% is life. Never made sense to me why you’d shine the light of a thousand suns in your eyes then put sunglasses on it because “it’s too bright” when you could just not.

My partner is a dark mode user and honestly sometimes her phone screen lights up the whole bedroom. Even with dark mode. I don’t understand.

I'm with your wife on this one, and also either one of those is way better than "grey on whatever" that seemed to be a prevalent design choice for a few years for many websites.

Low contrast is hell.