There was a brief period where the ultra-intelligent switched to the highbrow game of the Eastern world, Go, likely due to its greater difficulty at grandmaster levels, and its well-established handicapping system that allowed for entertaining games between people of different skill levels.
Now, there are thousands of games played by elites, and none of them have such a clear advantage that anyone would put their leaderboard position on their resume. I already know how to play Chess well enough to let my boss win (without making it obvious that I threw the game), and I have plenty of other games that I can play when I actually want to have fun.
So why would I spend any more time practicing just that one game? I could try to improve my Go ranking, or play Hive, or build a new M:tG deck, or get better at Risk.
Many of the reasons people had in the past to play Chess well are no longer applicable exclusively to Chess.