In that Callisto benchmark, Vega and the RX 580 are positioned relative to Turing exactly as their averages were four years ago, if not slightly better. It's the 1080 Ti that's missing some performance, but not much.
I'd argue that's slightly subpar driver support for Pascal instead of a lack of features hampering it.
Also, the game looks fairly good in Lowest compared to Ultra+RT much like APT:Requiem. Am I the only one thinking it's insane to go for 144 fps here instead of, ahem, the cinematic experience?