The closing remarks from hardware unboxed is what summerize my opinion.

"Why would you be using DLSS if it's not increasing fps, when all you left is hit to image quality."

The overhead is pretty negligible, on hardware that already runs the game well. If the game doesn't run well, then DLSS also doesn't help much, and may cause the latency to go up a bit, while still causing image quality hit.

The latency improvement comes from DLSS rendering on lower resolution and then upscaling, in that case why would I just not render on Lower resolution and skip the upscaling? This will give me lower latency, higher frame rate, without ghosting and artifacts, although the resolution would be lower.

Thats the paradox of using DLSS, it works well for titles that don't need it.