Problem is it's not just RT alone now like it used to be, we now have addons/extensions that improve RT, Ray Reconstruction, ReSTIR GI, RTXDI, SER etc. The first one is especially important as it makes ray traced denoising go from noisy to clean which is most obvious in unreal engine 5 now due to the way Lumen works. On top of that Nvidia helps any dev and provides all the tools free to add this stuff into their game engines, on the flipside AMD have been said to just go here is FSR3, it's open source, you can make it work" or words to that effect based on past dev chatter online and interviews etc.
This is currently only possible on any RTX card, not just the 40 series, So yes whilst a 7900XTX can match a 3080 Ti for base RT, it can't match it for clean RT due to the above. AMD need to pull their finger out and come up with a similar method to do the same thing, perhaps even use the same thing using their own RT hardware.