Here is the fix for ugly fonts on non retina in Mojave

[hackmefrancis]

I'm not sure if you are aware of this in System Preferences/General? Works well on my 4k Dell monitors... give it a try, you might have to logout after changing it.
View attachment 375347
View attachment 375346

May I know what resolution you are using?

 

[jb007]

May I know what resolution you are using?

I use the native resolution of 3840x2160@60Hz but scaled to 1920x1080 so I can read the text comfortably.

 

[hackmefrancis]

I use the native resolution of 3840x2160@60Hz but scaled to 1920x1080 so I can read the text comfortably.

Oh okay. I wondered coz' I also have a 27" 4k monitor scaled to 1440p and the text isn't crisp enough. Icons or UI in general is crisp though.

 

[jb007]

Yes that always a problem when you use a fractional scaling rather than a integer scaling. My 2 Dell 4K monitors always look best when scaled to 1920x1080 which is basic pixel doubling.
Another thing us as I understand it is macOS displays the fonts as per the way the font designer intended ie if the outline occupies a half pixel then it tries to draw it as such. Windows TrueType modifies the font slightly to make it fit better within the pixel grid and also used other methods to smooth the image.
Now that Windows is getting better at displaying on HiDPI monitors the fonts are looking better than macOS especially at scalled resolutions. Also I think the font choices are better in Windows.