Its common sense really. First, have it at the back of your mind that consoles always push above their weight, this can simply be attributed to better optimization. Then lets move forward.
At 16.75TF, this puts the PS5pros raw raster perf in the ballpark of 4070 (14.5TF) and 6800XT (20TF). The 6800XT is similar to the 4070 in raw raster performance workloads But grossly gets outperformed when RT workloads come into play. Eg, AC:M non-RT at 1440p; 6800XT 86.6fps, 4070 97fps. Or Avatar with RT@1440p; 6800XT 45fps and 4070 52fps.
So, the simple deduction is to find an AMD GPU that has similar raster performance, and if the PS5pro is to have RT performance that is 3-4x better than that found in the og PS5, then you will end up with a GPU that performs like that similar Nvidia GPU in rater and RT performance too.
Just looking at the TF numbers alone, will put the PS5pro based on RDNA 3.5, in the ballpark of a 4070. And you would need a more powerful AMD GPU from a TF standpoint alone (in this case the 6800XT) to match that kinda performance. Asssuming no RT is being used. But further more, you can also factor in things like the fact that on consoles,, they willl not be running any or everything at ultra settings. And will also use dynamic resolution scaling where applicable because yes, its targeting 60fps. And that is how i arrived at my 4070 levels of performance.