The checks on certain traits and skills you may have that bypass thing that could gove shottcuts or prevent a fight, e.g Starfield has a LOT of points where persuation would prevent a fight from breaking out, get you more credits, or offer an alternative solution to a conversation.
And its not like I havent played either game, ive already finished both CP2077 and Starfield effectively (minus the recent 2077 expansion)
I dont believe fluid frames reuires motion vectors as a hard requirement, else the driver level option where you force a game to use the function would never work (which is a feature).
However so far, fluid frames is only available on DX11 and DX12 titles, so many emulators would not have acess to the option. Switch emulation, and PS3 emulation which would need it the most, dont use directx