Well, no, that's the problem. It doesn't.Nice to see you're keeping an open mind on the subject, lol. But seriously, the fact is that The Witcher 2 has plenty of textures, assets, and post-processing affects that are higher quality than those in The Witcher 3..
Ubersampling, by the way, it's just downsampling under a fancy name.
You could apply it even to TW3 through drivers, external tools or maybe even just ini tweaking, if your hardware could manage it (which is unlikely).