If you are curious between the dithering in epsxe and how other emus do it and how a psx does it,here is a comparison
For further footage on dithering(and if you want to compare epsxe with pcsx on dithering),watch this video
https://www.youtube.com/watch?v=iOdANZHrbNw
(watch at 720p)
About anti-aliasing,i think you can have it both with dithering.
The dreamcast uses both dithering and anti-aliasing
The psp has dithering.PPSSPP can display this dithering plus it also supports the FXAA shader(a type of anti-aliasing)
using FXAA on ppsspp does not make the dithering disappear