https://www.pcgamer.com/pubg-is-the-third-highest-earning-game-ever-on-steam-according-to-gabe-newell/

At a roundtable interview at Valve's studio in Bellevue, Washington today, Valve founder Gabe Newell noted that the company created a "hole" by not shipping any new games after Dota 2 (and says they're going to start doing that again), but also took a little credit for a game Valve didn't make.

Valve's hardware and technology research has been an "investment in the future," said Newell, one which he connects to the incredible success of PUBG. "[That investment] does help do good things for the gaming industry. So you can have a relatively new game like PUBG, and because they can capitalize on all the other multiplayer games, the technology, the fact that China is now a huge market for anybody who does PC game development—So PUBG can come out of pretty much nowhere and become the third largest selling game in Steam's history. Their gross revenue over all time is already number three in fairly short order."