PlayerUnknown's Battlegrounds, or PUBG, has been one of the most successful games ever released. Since its debut in mid-2017, it's had astronomical player numbers that made it by far the most popular game on Steam for well over a year. However, its time in the sun may be gradually coming to a close, as following a steady decline throughout 2018, the game has failed to reach a million concurrent players for the first time in more than 12 months.
That's an amazing achievement and certainly isn't any indication that the game is dead, but it's fallen far from its peak and if the trend continues, PUBG may soon become a game that is merely popular, and not monumentally so.
Initially launched as an Early Access title in April 2017, PUBG's rise to prominence was gradual at first, gathering a few hundred thousand regular players by the middle of the year, but it was as it drew to a close and the second rolled around that was saw the most growth. Between September and December 2017, PUBG went from a million players to close to three. It eventually peaked at 3.25 million concurrent players in January 2018 and from there it's steadily declined. There was a big drop off in March, but it swiftly recovered to the mid two millions, but again, with regular peaks and troughs, it dwindled lower and lower throughout the last nine months to where we're at today.
The drop off has been much slower in recent months, falling from 1.5 million in June to just less than a million now, so it may be that we're soon to reach a point of equilibrium, where new players coming to the game are able to replace those who continue to leave, much like big MOBA titles like DotA 2 and League of Legends have done in recent years.
As for the battle royale genre, Fortnite has clearly taken the reigns there and will likely continue to hold on to them for some time to come.