Not really. Sound cards are really only useful for audio/video production. Onboard audio has made leaps and bounds over the last decade, so it won't really help with positional awareness or audio clarity.
Given that you are at the semi-pro level, you *might* find it as a benefit, just in terms of the software support and being able to tune the EQ to better hear particular SFX, like an enemy gunshot. But I still don't really recommend it. I think your money would be much better spent elsewhere like your monitor, mouse or keyboard.
If you want more info, here's a good video about exactly this subject:
https://www.youtube.com/watch?v=SFBvvlebSmw