https://www.youtube.com/watch

At max settings, you can average about 150fps in OW.
When buying this screen, your priorities should be clear.

I bought mine for CSGO. Not for the good resolution but so that I can take full advantage of my FPS.
If you want to play everything at full resolution and highest quality, a 4k with less Hz would also be an option.
Competitive <--> Experience has to be decided.

To answer this question I need more information...
Which game? CPU? RAM? etc.
Basically yes... but as I said. Depends on the rest of the specs and the game.

Small tip: On youtube you can often find FPS tests for many games with all possible specs. So you can estimate well how your PC will perform ;)