The main benefit of playing in a borderless window is so you can do other stuff while you are playing. i.e. for users with multiple monitors they can have a browser open, spreadsheet for their commodoties, podcast/music controls etc. on a second monitor. If you are running full screen you can't pull the mouse on to a second screen without alt-tabbing or hitting the windows key.
The main benefit of playing in a borderless window is so you can do other stuff while you are playing. i.e. for users with multiple monitors they can have a browser open, spreadsheet for their commodoties, podcast/music controls etc. on a second monitor. If you are running full screen you can't pull the mouse on to a second screen without alt-tabbing or hitting the windows key.