Why is the Battle Royale Game genre so popular?

One of the newest genres to really “blow up” on the scene, thanks to PUBG and Fortnite (and Realm Royale, I hear you), is the battle royale. While it is a new genre, it contains pieces of other existing genres (as most new genres do). What does the Battle Royale borrow from other genres and what does it exclude? What does it add? Form an argument for why it is so wildly popular right now (if you Google “Fortnite” you might find articles that will help you).