I know I'll be seen as an Apple fanbot for saying it, but holy schmoley Apple's operating system-fu just leaves Windows in the dust.
Macs are great and so is macOS, but it's not that good, at the end of the day it's just a computer
(Run non-retina displays at 2X frame buffer for proper anti-aliasing)
Edit: Also want to mention that window sizes and various UI elements also snapped into their 'intended' locations. Two screens, both 1440p, one ultrawide for anyone reading. YMMV.
1. https://github.com/waydabber/BetterDisplay/tree/opensource
This sort of app might get a better output by forcing the 2x rendering and then scaling it to the native display resolution but it cannot possibly be of the same quality as what we had before, unless they rewrote rendering or something like that.
As far as I know there are 2 "real solutions": you buy a display that is retina class in one of their historically supported resolutions or you accept to lose a bit of desktop space by running a "sub-retina" class display at x2. For example, a 27 inch "4k" (they are 3840x2160) display will get you a desktop space of 1920/1080 in HiDPI mode. That is sad because a 27-inch iMac from the early 2000 had more desktop space, an image not as sharp but it wasn't bad as long as they kept sub-pixel antialiasing.
As far as I'm concerned, it is that way because they went the lazy way around implementing HiDPI and being able to market it like they were so much better than Microsoft. But that only works if you solely buy their hardware because nobody followed them on the desktop specs (even though it's slowly coming lately it seems).
This issue in my opinion is a testament of how much anti-consumer and disdainful Apple is; because it couldn't possible have cost them a lot of engineering to be able to support both, it is clearly for their bottom line and that's it.
...for now; until Apple disallows any kind of system extension or desktop UI enhancements.
From reading the comments in these threads and some additional resources, it does seem that the problem is not whether or not the display is “retina” per say, but that macOS is designed to run on high density displays and can have problems with low density ones. My mistake I guess.
I think the point that Apple should have better support for a wider range of displays still stands. It is not unreasonable to want your general purpose, professional-grade computer which costs thousands to work correctly with a variety of displays and resolutions, especially when lesser machines do it better.
At this point I’m just whinging bitterly though, the blurry icons are not the end of the world and buying new displays or a new computer just to fix them would be silly.
So on phones it has usually been about 300dpi. On laptops and desktops it's been something over 220dpi.
Apple has is actually enshittifying too (dumb UI changes, worse apps - see "Catalyst", etc), it's just that Microsoft has became a trailblazer in that field so Apple still feels good in comparison, despite the many downgrades.