There’s a great article with explanations on the net. But the gist is that macOS renders like a giant image with no care for pixels and small details. It works fine when using native resolution (low dpi) or have enough pixels for their “retina” approved resolution. Anything else and it looks blurry.
Linux and Windows use actual pixels for their rendering, and even with anti-aliasing, it looks sharp. If you’re stuck with macOS, aim for 4k at least.
Ideally, you want a screen that natively runs at a resolution that’s a perfect 2x multiplier of a mainstream 1x resolution that has the right amount of screen real estate for the screen size.
So for example, a 20”-24” screen should be 4K so it can run at 1920x1080 @ 2x. Similarly for 27”, you want 5K which is 2560x1440 @ 2x.
This is a really good post describing how it all works:
That’s the article. I got hit with this issue after purchasing a 27” QHD monitor. Native resolution made everything too small, and everything else was blurry. I gave up after trying pretty much everything and bought a 24” 4K monitor for the mac.
Linux and Windows use actual pixels for their rendering, and even with anti-aliasing, it looks sharp. If you’re stuck with macOS, aim for 4k at least.