I was actually thinking about World of Warcraft when I was thinking about a game that failed to be sticky. World of Warcraft peaked in subscriber count in 2010, and has generally seen steady decline since then. I think the numbers for WoW look worse when you consider how sharply it's share of the video game market has declined. The video game market has ballooned in size while Wow's user base is slowly bleeding out.
It's hard to get accurate data, but Fortnite has roughly 100x more users than World of Warcraft. Counterstrike is an even smaller userbase.