The FF16 demo is absurdly heavy. I was getting ~ 120 fps at native 1440p with frame gen, which is almost on par with Black Myth Wukong's at Cinematic + RT at similar settings. That's with insane hardware, can't imagine how is it going for the average dude.
I had Lossless Scaling in the background to double the framerate of the 30 fps cutscenes too. It's a bummer they aren't capped at 60 instead.