I find these percentages somewhat infuriating and useless, because it's completely unusable out of this exact context. So let's convert it to milliseconds. The article shows his "native" averages (1440p) as 230 FPS without, and 93 FPS with DLSS 5 (I assume he's referring to just the AI filter here).

230 FPS is ~4.34ms/frame

93 FPS is ~10.75ms/frame

So it takes about 6.5ms to do its thing on a 5080, without frame generation or upscaling. That's.... pretty bad. 120 FPS (8.8ms/frame) would be basically impossible, and you'd need to be at 100 FPS without it to get 60 FPS after this does its thing. Assuming you even like the output, which is a big if, this is a pretty hefty performance penalty to pay for it.