The new drivers do increase performance but mess with the lighting and therefore make the experience almost unplayable. Hopefully AMD knows this and gets to work on it with Eidos. For now play with 21.10.2.
Thanks for posting. I was just about to start a new thread. The game does run significantly faster on the new drivers, but like you said, the lighting is completely broken. On 21.10.2 it's playable at 1440p all ultra, rt high, on my 6900XT, but does dip into the mid 60 in some spots. Hopefully AMD can roll out a hotfix quickly. Game itself could also use a few patches!