Performance Scaling series Radeon RX 6700 XT
Performance Scaling series Radeon RX 6000
Once we take the result sets from all games and resolutions we can math some numbers. Of course, you'll gain a lot of FPS when rendering at Full HD, however, the image quality loss in our opinion is just too big of a jump. If your native resolution is QHD, then Full HD might be an alternative to check out though.
However, if you have Ultra HD as native resolution and a game that doesn't perform well enough in that resolution, then select a monitor resolution of 2560x1400 (W)QHD. You'll average out at an 81% overall performance increase.