I think two games came close to offering the speed & fluidity that QW offers.

One is CPMA (http://playmorepromode.org/) which is basically Q3 with QW physics. It's based on Quake 3, which I was never a fan of, and really fast & fun!

The other one is Warsow (https://www.warsow.gg/). I enjoyed playing this game a lot, but I think a lot of us got bored at version 0.4 or 0.5 when it seemed to become more "beginner friendly" and less... fast. (If there's any Warsow players in here you might remember eml from bolted.nu :)

I still watch QW games occasionally, especially duels. The longevity of the game is insane. Seems to me that the FPS duel genre is dying off though. (Not that I follow anything closely anymore.)