It’s the difference between reading text on a piece of paper printed via a modern laser printer and an old fashioned dot matrix one. They are both readable, but one looks much better than the other. You change test this by printing out a screenshot of a PDF vs. printing the PDF out directly.
And yes, I use matte filters on my high DPI screens, especially my iPad.
And an offset-printed book page will look "much better" than even the laser-printed one, but do people really care at that point? That's pretty much the same as complaining that a 4K resolution is too pixely.
4K is too pixels if the screen is large enough. I had a Hitachi 28” 4K before I upgraded to an iMac 27” 5k. The text on the hitachi looked like crap, you could see the pixel corners and sub pixel anti aliasing coloring bleed through 10, 12, and larger fonts (that is on Windows, on a Mac you would see lots of blurriness via font smoothing).
Aesthetics matter, for a few hundred dollars more, it feels like I’m almost looking at paper (if it weren’t for the backlighting).
DPI is only half of the picture though (forgive the pun). Viewing distance is the other half, your eyes can't tell the difference between 100 DPI and 300 DPI if you're far enough away.
So what, do you read books ten feet away to reduce eye strain?
A modern desk gives you about two feet between you and your monitor, which isn’t overly close, and you’ll still very much notice the difference between 138 and 220 DPI.
Bingo. And it's less stressful for the eyes to focus on an object that's further away. Net result: I might actually have some vision left over by the time I retire. Worth the cost.
Yeah but we're talking about computer screens, not televisions. The viewing distance is around 20-30 inches and 100DPI definitely does not cut it at that distance.
