For example, my PC meets the minimum system reqs for CKIII. This should mean that CKIII can run in my PC with lowered graphics (but who cares really?) but no/minimal lag. I am making a satisfactory graphics trade off, and I don't mind, so this is correct.
Unfortunately, due to a hell of a lot of calculations being CPU-bound, not GPU-bound, dropping your graphical quality may not decrease lag.