Detail hardly matters, only total number of pixels. I get the same as you with a 2070s. It's just poorly optimized, still.An i7-10700K and a 2080TI are not enough to play this game in 4k on the "Low" details preset inside the lounge areas? Seriously?
That's it. I'm done. You will get a final chance, when the console version is released. Good luck.
Edit: I get ~ 40 FPs on "Low" and ~ 30 FPS on "Ultra".