RDNA 2 vs Ampere major difference is that FP32 X 2 of Amepre, which is why in most of recently released game it is betting it's equivalent more than 2020, 2021 AAA game release. Expect Call of Duty Modern Warfare 2, Nvidia RTX 3080 has beaten AMD's RX 6800 XT 90% of time in AAA release of 2022 ,however, in 2020, 2021 RTX 3080 was mostly equal to RX 6800. Reason is because Nvidia has more Advance Hardware than AMD expect Vram Disadvantage that is why AMD made changes and RDNA 3 is also FP32 X 2 copying Nvidia method.We have a few clues. one is that the difference between RDNA2 and Ampere, remains similar with and without RT in Spider-man. While on other games using RT, the difference is much bigger.
The other is that the amount of data transferred between CPU and GPU, through the PCIe bus ramps up much more than on other games using RT.
And finally, because Nixxes told so to Digital Foundry, being one of the reasons why this game is so heavy on the CPU. At minute 21:35