Let’s look at an example video, below. The left side uses Control’s in-engine scaling. The right side shows DLSS. Both sides are rendering at 720p, and outputting at 1080p. Notice how DLSS brings out more detail and improves temporal stability, reducing flickering and shimmering.
But even NVIDIA admits DLSS isn't perfect:
While the image processing algorithm is a good solution for Control, the approximation falls short in handling certain types of motion. Let’s look at an example of native 1080p vs. 1080p DLSS in Control. Notice how the flames on the right are not as well defined as in native resolution. Clearly, there’s opportunity for further advancement.