The real reason you can’t carry over your Fortnite: Battle Royale progress on the PlayStation 4 to another console? The PS4 is just better and Sony doesn’t want you wasting your time with inferior platforms.
That’s the reasoning given out by Sony CEO Kenichiro Yoshida, who said in a conference in Berlin last week that
“On cross-platform, our way of thinking is always that PlayStation is the best place to play. Fortnite, I believe, partnered with PlayStation 4 is the best experience for users, that’s our belief.”
Of course, some might argue that being able to use the items you purchased on your PS4 version of Fortnite while playing on your Switch is the “best experience for users,” but what do us silly users know?