as many other will argue - accepting such crap as "reality" has become a really bad trend.
Stable, I dunno, but generally mooth gameplay, yes. Unless the game hates nVidia for whatever reason 
I playing medium 1080p on i5 2500k stock & RX580 stock which is way slower than yours.
Frankly, from what I see, the differences between medium and ultra (non RTX) really isn't that big, I took screenshots to compare and the only noticeable differences is amount/accuracy of shadow.

I turned down all the cascade shadow setting, ssao low, but crank up the screenspace reflection quality to reduce the graininess of it (didn't affect performance much).
Obviously turn off those annoying post process like lens flare, chromatic aberration & film grain - they are seriously overpowering.
Also use this to turn of TAA if don't like it : https://www.nexusmods.com/cyberpunk2077/mods/81 I forced MSAA in driver but not sure if it even works, nevertheless I'm not too bothered by the aliasing problem.