And the crazy thing about that is that Windows handles fractional scaling perfectly, and I hear that Linux environments mostly do (but I have no experience), while macOS uses an absolutely stupidly bad technique that literally makes the higher resolution worse than having a lower resolution screen in most cases: rendering at the next integer, and scaling down. That way, it’s impossible to draw pixel-perfectly, and fine detail (like text) is always blurry. The mind boggles and I still have trouble believing that they actually did this, when their grip of their ecosystem made them the OS in the best position to do it right.
macOS uses an absolutely stupidly bad technique that literally makes the higher resolution worse than having a lower resolution screen in most cases
That's not my experience at all. For a while I was using a 27" 4k display at an effective resolution of 2560x1440. Obviously it wasn't as nice as 5k at 2x scaling would have been, but it was much sharper than a native 1440p display.
I think you misunderstand what's happening with macOS resolution scaling. What you're describing is assets being rendered down and getting blurry; but this doesn't happen to text because text is vectorized. You're right that some assets like icons and such will be less sharp at 1.5x than 2x, because 2x will have an actual asset and 1.5x will have to be scaled down.
How does Windows fix this? I have used so many Win32 apps that are jus broken in one way or another on HiDPI displays, most shockingly Visual Studio, my experience of HiDPI on Windows is always worse.
I've had better luck with fractional scaling on Windows over Linux. Can be hit or miss if any given Linux application will handle fractional scaling well, but the desktop environment (KDE Plasma on Ubuntu) does fine with it.
My experience with it and multiple screens is not great.
Not sure why it is that way - it's just a matter finding a global pixel size, rendering all screens to these bitmaps and then 2D scaling them down to panel resolution.
