increasing your display resolution makes images and text appear smaller on the screen. Higher resolution increases the pixel density (PPI), meaning more pixels fit into the same physical space, causing images to take up fewer inches of screen real estate. Conversely, a lower resolution makes items appear larger.
By todays standards 75hz is limiting. In fps anything over 75fps those extra frames are discarded. Its a bottle neck to any new GPU. You can have a GPU that does 300fps, you’ll only see 75fps, no matter what the game says, the monitor is last in line