@lispi314
I suppose a follow-up is in order, eh?
There really wasn't a good explanation for why a game like that would strangle a 3060 on default settings. But a particularly sharp cookie brought up one point in particular.
If System Shock is taking the lion's share of the GPU by simply running on defaults, and OBS is only capturing the game at 60fps for the purpose of streaming, then just lock the game to 60fps as well.
As I have 144Hz monitors, ths cut System Shock's usage by over half. Because... well.. it's drawing over 50% less frames.
The game has no way to set frame rate, so I used the launch option DXVK_FRAME_RATE to limit it.