Sadly and relatedly, the Descent series (6 degree of freedom FPS) was an intense test of skill unmatched anywhere else, and the last release in that series was

Sadly and relatedly, the Descent series (6 degree of freedom FPS) was an intense test of skill unmatched anywhere else, and the last release in that series was ~13 years ago. I don't know of any other newer games in the genre. Competitive FPS gaming reached a peak around 1998. Since then, the only games I've heard of with similar high-level competition have been in the RTS genre. "Watered down" seems to be the name of the game nowadays.