1440p is hugely common on gaming laptops. Alienware M15, Razer Blade 14/15, Lenovo Legion 5, etc... all offer displays in the QHD or WQXGA range.
The reason you typically see 1080p or 4k on ultrabooks is because 1080p is how you get the low entry price, and 4k is what sounds better on marketing and looks the best for text-related things (4k is not at all useless - the sharpness it provides to text is noticeable). The balance that QHD provides isn't very desirable in that market usually, although there are exceptions like the Framework laptop or the Surface Laptop 4. Usually those exceptions then also come with more unique aspect ratio displays like 3:2, though, so they aren't exactly 1440p/QHD. But they are in that density.
Resolution is independent of size. Just because it doesn't work perfectly on Linux high DPI is much nicer and easier to read.
The decapsulate on of resolution and size is btw already quite old. Games have this as well were they dynamically change the internal resolution but not the screen resolution.
And you might not care about it but:
- text is much smoother
- images from DSLR have higher resolution than 4k for ages and you can see the difference
The only arguments against 4k on smaller screens should be power consumption and not scaling issues. But for this we should focus on dynamic refrehsrates and similar power saving mechanism and again NOT complaining about 4k.
MacOS is doing this flawless for years. Windows can do it and under Linux it starts to be usable based on comments of this article.
If somebody understands the situation better on MacOS I'd be interested, but based on my experience, Windows is the only OS that gets this as close as possible to right. It's a single setting that affects all applications and I can set monitors independently and it will scale on the fly (even if it does look a little weird as you drag an app across and it dynamically shifts)
Every now and then I'll come across a app that doesn't quite deal with high DPI scaling correctly, but it is the exception to the rule.
Linux also works pretty well, but as with everything Linux, it's almost always "it depends and well, not quite" (not usually multi-monitor aware, lots of per app settings)
I'm not really sure what you think 'scaling' means or what you think this Stack Exchange answer means, but macOS (not 'MacOS') does allow scaling the UI of both integral and external monitors, and independently.
It renders a high-resolution image to a buffer, and then scales that when rendering to the actual screen buffer. The buffer image is at least as large as the actual screen buffer.
You can see for yourself that it isn't changing the hardware resolution of external monitors when scaling by taking a look at the actual resolution on your monitors OSD if it has done. It'll always be the native resolution.
Again I don't really know what you think you mean by 'blurred'? How do you think this is working?
If I tried all the possible scalings for my external monitor, the grey line around each window, to give a specific example of, is always a crisp physical one-pixel wide.
macOS creates a buffer to render to that is the same size as the physical output you're choosing to use, and is able to render with pixel precision in that buffer.
In Mac OS, because that's how its scaling is designed. Windows does not have this problem, because it tells programs to render themselves at 1.33 or whatever and provides facilities to do it without pain in the ass. As the result scaling in Windows is painless with any displays at any resolutions. In fact, my main setup has two 1.25x DPI displays and an old 1x DPI display with zero blending or sizing artifacts excluding brief moments when you move a window from 1.25x display to 1x one until it lands.
What? MacOS does scale. MacOS was doing this correctly years before Windows!
First of all, DPI is not the metric we're interested in. That is a unit for print quality, and it has no relevance for an OS, for Photoshop, or anything we do on a screen. The operating system does not know how big your screen is. Inches nor dots are relevant; only pixels are. It would be more accurate to talk about the ratio of monitor pixels to apparent pixels. I guess Microsoft finally got the memo in Windows 11 (or was it 10?) and changed to percentages.
In MacOS, a 4K monitor set to 1920x1080 will still be 3840x2160, but it displays 4 pixels for every 1 apparent pixel. Everything scales correctly, except for legacy applications. The UI elements, text, etc. appear to be a sharper version of 1080p. In Windows land, this is the same thing as "200%." As far as I can tell, Windows does the same thing but uses scaling percentages instead of apparent resolution.
Your only problem with Windows appears to be that it named the scaling setting "DPI" until Windows 7 or so to handle scaling. But as the parent mentioned, Windows is definitely superior to MacOS, as it provides arbitrary scaling ratios, and renders text perfectly at any ratio.
To go deeper into nitpicking, DPI is not even that misleading, if you take "inch" in DPI to be equal to 72 points as used in font sizes. Then a 72pt font on the screen with DPI X will be rendered with height of X pixels.
DPI is a valid metric for anything that the human eye sees. There's no difference in that regard between text printed on paper, and text displayed on the screen. The smaller the dots, the better it looks.
The problem of 4k is efficiency. 1440p is already 2x at 14 inches, which at normal viewing distances is about as sharp as people can see. Going up to 4k does not really improve visual quality, but it dramatically increases the pixel count that must be rendered, which burns through a lot more power. 4k laptops have worse battery life and worse display performance than 1440p laptops, but they offer no upside for those downsides.
There is a reason macbooks, still the gold standard for hi dpi rendering, have never had 4k panels.
The reason you typically see 1080p or 4k on ultrabooks is because 1080p is how you get the low entry price, and 4k is what sounds better on marketing and looks the best for text-related things (4k is not at all useless - the sharpness it provides to text is noticeable). The balance that QHD provides isn't very desirable in that market usually, although there are exceptions like the Framework laptop or the Surface Laptop 4. Usually those exceptions then also come with more unique aspect ratio displays like 3:2, though, so they aren't exactly 1440p/QHD. But they are in that density.