Graphics get worse if you cap your fps high, I have not changed anything other than the fps cap and yet 45 fps looks 10x better than 90 fps, I feel like
The Do's and Don'ts of reaching 360 frame per second in-game | ZOWIE US
How to Fix 60 FPS cap on Fortnite - YouTube
60 FPS vs 144 FPS: Does Higher FPS Actually Matter? - PC Builds On A Budget
No matter the graphical setting, the FPS seems to cap itself. Hope this helps in finding a fix! : r/FORTnITE
Fortnite's new 60fps mode is the real deal | Eurogamer.net
Fortnite can now run at 120 frames per second on next-gen consoles - The Verge