>>352783937
most games have graphic settings which let you configure what resolution to render the game at e.g. 0.5x downsample would render the game at 720p resolution but the game is borderless at 1440p. massive framerate boost but the game looks more pixely. 

this situation you are in is not unique simply because you are going from 1080p to 1440p. even games on 1080p need their graphic settings fine-tuned for optimal frames, you'd be doing this no matter what choice you made.