Create a twitch account and look at the top streamed games. Which by far are multiplayer games, singleplayer is a niche
Pubg is what started the battle royale hype. It is semi-realistic and definitely no arcade shooter. It is thus loved by a very hardcore kind of crowd. The goal is to loot as much as possible the first few minutes (you start with nothing), then start killing while you keep on looting.
So then there is fortnite, the (Chinese?) arcade and cartoony version of battle Royale, trying to reach a wider audience $$$. Now there is this new beta realm royale that everybody plays.