I haven't found a use for…
Maybe I'm getting my terms confused here, but upscaling to me means rendering at a lower resolution and then upscaling that to a higher one. In that case 4K would be the ideal use case, as the GPU could render at lower resolution then DLSS/FSR upscale it up to 4K at better frame rates.when nvidia first introduced upscaling, I had a GTX 980 so I could have used it except native res of monitor was 4k and I couldn't make that any better.
By time I had the 2070 Super I had swapped displays to 1440p and Frame Generation may have been useful on it to get it closer to Monitors max speed
Now I have a 7900 XT and can run screen at max speed without any features. I would like to see them but really no point. Might be a few years before I do.
I seem to keep missing these features. I need a 4k fast refresh monitor to really see them now, and I don't really need/want a new monitor now.