hi,

when i open a pdf document side by side in Okular and Foxit Reader the text quality in Foxit is much smoother and nicer to read as it has RGB antialiasing whereas Okular has grayscale. Why can't Okular respect the subpixel AA options set in KDE Plasma or .Xresources?

Okular for me is a disappointment as it has great features, great UI, but the core feature of text rendering is ugly!

Firstly...
the last time I used Foxit was way back in my Windoze days
(so thanks for the reminder)
unlike yours, I have other issues with Okular
anyways
I installed Foxit and have--for the time being--it as the default PDF reader

Secondly...
after reviewing a number--of varying quality scans--of PDFs
I did not see what you say you experience
all PDFs appear the same in both apps
(even poorly scanned low-quality PDFs render the same)
I am assuming that you have configured
(a) the backends to your font prefs
although in my experience, that is not the cure for low-quality PDFs
(b) the Sub-pixel rendering of your Font Settings