I would say phones would be an exception to this rule, since a large number, perhaps even the majority, use OLED panels which are capable of displaying true black. This is becoming true for TVs as well.
An OLED or LCD panel, even one that is entirely turned off, isn't "true black". If you put something like Vantablack next to it, it would become very obvious that it's merely dark gray. It's still reflecting a significant amount of light from the environment.
And then it appears even lighter when you've got "black" text on a white background, because on our retina the white background "bleeds" into the black as well.
Painters, photographers -- these people are very aware that with real-world common objects, "black" is never actually black. Unless you're literally in a room with no light at all, it's only ever dark gray. Computer screens are nowhere near capable of producing any kind of "unnatural true black". It's not a thing to worry about.
We're talking design here, not physics.
It's a bizarre idea that started gaining traction maybe around 5 years ago, that using #000 in designs is therefore bad because it doesn't occur in nature.
That's what I'm pushing back against. The #000 on your screen does occur in nature, because its output on your screen is just a normal household black like lots of other objects.
Yeah, something like 10 years ago there was a web designer who took an Art 101 class, where the teacher told them to never use pure black paint. Because black objects in the real world appear to the viewer as a dark gray.
This is all true! On a canvas, painting a black car—which uses actual black paint in real life—using pure black paint, will not look right. The painting is supposed to "have its own light" included. So you must represent what the object would look like under the lighting conditions of the world you're recreating. Highlights are not different colors in real life, but they are on a painting.
But anyway, so this web designer, fresh from his Art 101 course, decided to write some blog post about it, and it's been accepted wisdom ever since.
1) We're not painting cars here, we're writing text. I don't load up "dark gray" ink in my fountain pen, nor do I use a "dark gray" toner in my printer. I would much rather the text on my screen be the same.
2) Contrast is good for legibility. Make the contrast as sharp as possible. Or, if you don't want that harsh look, then darken the background instead of lightening the text. Not too much, just enough to please your aesthetic sense while maintaining readability.
Yup. Agreed across the board.
Displays do have technical issues. CRT's bloom on high contrast elements. I just read OLED ghosting is a thing when pixels are full black, not driven, as examples.
How to best handle those makes sense.
There are technical reasons to avoid both extreme white and black. Discussing those makes sense.
Same with grays. Grays look better when you add a subtle amount of blue to them, instead of plain ass grays. Cold grays look better.