You have a nvidia gtx, so I'm going to assume (hmm) that you also are using GeForce Experience, or it's at least operating. If you are, and especially if it's set to automatically optimize any games it finds/you download, then it's going to optimize to the best of its ability. On my gtx970, that means Skyrim was automatically set for 4k DSR, with max ultra settings, which uses a significant amount of cpu/gpu power (Skyrim isn't all that extensive on an i7/970 so I had plenty of power). It also gave a very good picture at the cost of some fps. And I run 1080p monitors. GE has extensive settings, far and above what you'll actually find in any game, so if your game doesn't have a viewing distance (for instance) GE does and it'll override the games coded default, because it's a gpu setting, not a game setting. It means when you set medium in game, the game only changes what it is coded to change, GE will play with anything else, on a gpu level. Many don't like GE, just for that reason, optimized games might look better, but perform worse than what the user is expecting.