I'm a software engineer and although I currently don't work on anything related to computer graphics, I understand I understand how downscaling works, what I don't understand is why most modern games default to over 100% on my computer (GTX 1080, 1080p@144Hz monitor). For instance, Overwatch defaults to 140% render scale, which translates into a huge performance hit (stable 144 vs 60~80 fps). Why is the game doing this? I understand that downscaling makes the quality of the image a bit better, but this doesn't justify that performance hit. I read in some places that downscaling also helps to reduce some graphics artifacts, can someone please elaborate on this? I would like to know what are the benefits of downscaling and why modern games are defaulting to settings above 100%.

I'm a software engineer and although I currently don't work on anything related to computer graphics, I understand how downscaling works, what I don't understand is why most modern games default to over 100% on my computer (GTX 1080, 1080p@144Hz monitor). For instance, Overwatch defaults to 140% render scale, which translates into a huge performance hit (stable 144 vs 60~80 fps). Why is the game doing this? I understand that downscaling makes the quality of the image a bit better, but this doesn't justify that performance hit. I read in some places that downscaling also helps to reduce some graphics artifacts, can someone please elaborate on this? I would like to know what are the benefits of downscaling and why modern games are defaulting to settings above 100%.