WoW 4k1 https://imgur.com/rYFbJBm
WoW 4k 2 https://imgur.com/tc2kMAN
Basically I think the main thing is lines being a little cleaner. It’s mostly like anti-aliasing.
This is 4k everything maxed, get a little over 60 fps on 5700xt. have it capped since monitor does 60fps.
Depending on game - FPS maybe greater than 144 might be useful. Probably only if you are competitive. For most people, 120 fps in a shooter is probably great.
For me, for RTS and MMO’s 60fps is nice, so 4k and a bit lower fps is fine. For wow I don’t think more fps matters much. Maybe competitive PvP, but even then I doubt it.