RTGI is already pretty much perfect these days if you do it right

Ray Tracing the entire scene looks great. It’s also way more computationally expensive than upscaling.

DLSS is just a shortcut, and shortcuts have costs. I don’t like the image quality cost so I don’t use DLSS (XeSS looks better anyway) and so I just buy more powerful hardware. Someone on a low-end machine can’t simply enable raytracing and still have a playable game, DLSS gives them more options.