Did you tweak graphics over the last while?
The Fortnite skewy-font appearance may change if
-- Display scaling is changed
-- Display resolution is changed
-- AA is changed (2x, 4x, 8x).
-- Detail setting is changed.
-- You turned off anisotropic filtering.
-- Or you followed some performance-increasing tip.  Some of those tips degrade graphics.
It can be hard to help without a before-vs-after photo.  All we see is the "after" (the problem) so we don't know what you were witnessing during the "before".   Also, sometimes it is indeed an OCD-factor, where you never noticed something until you suddenly started noticing.
Try maxing-out details, maxing-out resolution, maxing-out AA, maxing-out Anisotropic, matching resolution 1:1, and then you'll notice that fonts often look better too, even as the framerate drops like a rock.
This is really a manifestation of 
http://www.testufo.com/aliasing-visibility with 
AA turned on versus 
AA turned off -- where one is more noticeable than the other (making a skewy font look better versus worse).   You change a setting, then something became worse.
Here's some PhotoShop processing that produces a skew difference caused by an AA change:
Smart Scaling (Low framerate)
			
		
				
			 
- aa-on.png (4.39 KiB) Viewed 7495 times
 
Simple Scaling (High framerate)
			
		
				
			 
- aa-off.png (3.47 KiB) Viewed 7495 times
 
This might not be it, and probably won't help based on what I see in your screenshot.  But it's an unturned stone to turn, at least.