Supposed in that sense, it can be compared to how everyone played Pokemon Go because of how easy, fun and convenient it was Not to talk about how people had shittons of fun together. Even my mom played that shit. 
Pokemon GO is a good example, but they are restricted by Nintendo. Plus Niantic fucked up a lot, and their updates have been sllllooowwww (I've never played PKMN GO btw). Epic hasn't really done anything yet to garner negative media.
PUBG is still popular, some people prefer the realistic approach. But it costs money and requires a PC that can run it. Even PUBG on Xbox requires at minimum the Xbox X.
Fortnite runs seamlessly on PS4, PS4 Pro, Xbox, Xbox X, PC, iOS, Android... did I mention all you have to do is download it? And now it has cross-save, so you can take your Xbox/PS4/etc credentials and log on PC and have all your skins, settings and more available? I can now play with my friends on PC (Bore included) and everyone is none the wiser.
I've never played Fortnite btw