Is there another way besides the Mac App Store to get Fortnite installed?

While I haven't played it yet, I am interested in trying it. I understand it is free to play, and items like player skins can be bought in-game. So I'm wondering why Epic needed Apple's App Store distribution channel to begin with, but is it available for download by other means (maybe Steam, .dmg download, etc)?

Sorry if I'm asking something obvious to most gamers here. I didn't see a way to download an installer from Epic's site. Thanks.