I feel the system wide dark mode is the next step from Night Shift mode to acknowledge or encourage people to work more toward late night/evenings. Eye fatigue has been one of the reason my body reminds me to go to sleep, now I can maybe deal with some more emails before I head to bed.
Night Shift (and perhaps Dark Mode as well) work to decrease the amount of light towards the blue end of the spectrum as in the evening to mimic the natural spectrum shift and help people sleep, rather than mimic bright mid-day light. It's not to reduce eye fatigue and get people to work more: it's to help them relax and sleep better at night. Here's an article that discusses it in a bit more depth.
There is a growing body of evidence that cumulative lifetime exposure to blue wavelength light increases the risk of AMD. (Age-related Macular Degeneration, which can lead to blindness).
Hopefully they don't fuck it up like they did when they changed from high contrast to Smart Invert on iOS.
I used high contrast accessibility as a de facto night mode. In iOS 11 (or maybe 11.x?) they changed it to "Smart Invert" which tries to be smarter about inverting by not inverting the colors on images. Unfortunately it has all kinds of problems. Safari will randomly crash when viewing images. Sometimes is shows the wrong image (e.g. two images in a row and it will show the same image twice instead of two different images). Sometimes half an image will be inverted. Sometimes when I go back to regular mode the images will go into inverted mode. And it makes charts or maps with an HTML legend impossible to read because legend gets inverted but the image does not.
Try switching to "Color Filters". Set it to "Color Tint", turn the intensity all the way up, and set the hue to pure red.
Turbo-charged night mode. No "smart inversion" to worry about, no orange stuff that suddenly becomes screaming blue. Just a nice monochromatic red display that you can see in the dark without ruining your night vision or confusing your body's clock.
If that happens, I feel it's one of the good things, speaking from general perspective on how humans interact with devices. I'm a power user, who discovered f.lux around 3 years ago, and I've been hooked ever since. Around a year after, I converted my family to use whatever blue light restricting settings they had on their devices, and can say with confidence that it does help. I wouldn't say it's encouragement per se, more of a guideline that should be there in the first place. Most users don't care about colors being off at odd hours, as they're not power users, whilst power users will have the knowledge to turn this feature off. Raising awareness is not a good term, but I feel it fits in this case.
