After researching a little bit, less to my surprise, I found out that Apple has disabled Subpixel antialiasing for text in macOS Mojave. It’s gone.
Little more research led to a fix, all you have to do is open up your
Terminal application (COMMAND (⌘) + SPACE then search for
Terminal) and run the following command.
defaults write -g CGFontRenderingFontSmoothingDisabled -bool NO
This will lead to the font smoothing to be enabled — especially for non-retina external monitors. You’ll thank me later. You need to sign out and sign back in or restart your Mac before you can see your changes after running this command. That’s pretty much all.
⚠️ Some folks also recommended enabling the font smoothing option in the
General font settings but that didn’t work for me.