In Fortnite, when you make a custom resolution and stretch it, you increase the vertical FOV (Field of View) and squeeze the enhanced picture into the native 16:9 format. While this is true for CS:GO, it is not exactly the same for Fortnite. The second argument is that the player models become wider. This is mostly true since you will usually lower the resolution and therefore your graphics card will have less work to do and thus you gain increased performance. The first argument is that it increases the FPS (frames per seconds). There are two major reasons that competitive players are playing on stretched resolutions.
