It might be just me but I can't look at websites with black backgrounds and white or yellow letters. My eyes hurt and when I turn my head elsewhere I can see shadows of the website for a bit. I use dark(ish) themes everywhere but such high contrast somehow is too much.
i have exactly the same issue. so many websites nowadays choose to have dark themes which are essentially black backgrounds with white text and it is physically painful to read. if i'm invested enough in the article, i always try to change the user styles a bit to make it more bearable.
OTOH, deep-black backgrounds and green letters (with red/yellow/white highlights) is perfect if you're using an OLED screen. Maybe browsers need adjustable (and site-specific) brightness and contrast knobs, like monitors and TV's.