At this rate, Civilization 6 will have one by the end of the year.
As part of Dota 2's International 2018 Battle Pass, which will be available soon, players are getting access to a new game mode called The Underhollow:
Battle through a labyrinth filled with monsters, marvels, and many other three-player enemy squads as you search for Roshan's rarest cheese and work to be the last team standing. You'll need to navigate carefully to earn the XP and Gold needed to destroy your opponents.
But don't take too long - Roshan's cheese frenzy is causing cave-ins as he moves towards the center of the Underhollow. Soon enough there will be nowhere left to run.
Squads, a collapsing map, last-man-standing... yup, it's a battle royale mode all right.
If you remember, last year's Battle Pass also introduced a new game mode (a co-op story adventure) that was only playable while the 2017 pass was active, and was then removed from the game last September. So as current as this might be, it's also likely just a temporary diversion for DOTA 2 players.
You can check out some of the other stuff available as part of the pass at the game's site.