You don´t understand the real problem here.
People make an account on their PC for Fortnite. All the items and skins they buy carry with their account. Meaning if you play on PC and you jump on XBOX you get to keep your stuff and from Xbox you can jump to the Switch and keep your stuff. Now if you log in once on your Playstation with your EPIC games account it leaves something on your account that wil block you from getting your progress on Switch and Xbox from now on. So now you´re locked on PS and PC. It´s the most disgusting thing they´ve done in a while and I dont understand how anyone can defend this. This isn´t ´pro business´ this is anti consumer.
Except that if you first connect your account to your Xbox or your Switch you will not be able to connect with this account on your PS4.
If you blame to not be warned, blame EG, it's their page you see when you connect your account to a console network (but oddly they know how to warn when you want to disconnect your account).
You can from Xbox still connect to both Nintendo PC and mobile the fault is at sony´s there is no denying it.