Exactly this. Your systemAs previously mentioned, runs totally fine on my 1080Ti which is similar performance to your 2080.
Asssuming you're not using a potato CPU, there's something wrong with your machine or install by the looks of things.
I have a 2080Ti and went to Win 10 2004, it ran like garbage. It's my machine though, probably something like old drivers, I expect motherboard as I still run an almost 10 year old Z97X and i7 4790k. Reverted 1909 and it's fine.
Others on 2004 do not have the same problem, meaning it's my problem