To use an example from Assassins Creed Shadows disclosure on performance:
If we take AMD's most optimistic estimate for PS6 performance of 3x raster and 10x RT we would get on PS6
Screen space tracing 0.54ms -> 0.18ms
World space tracing 1.38ms -> 0.14ms
Lighting 1.17ms -> 0.39ms
Denoising 1.91ms -> 0.64ms
Total 5.00ms -> 1.35ms
Unfortunately there's no performance data for everything else in the frame, but IIRC it's a pretty stable 30 FPS on RT mode, so I think we can estimate around 25ms for everything else, so roughly 8.33ms on PS6.
So ignoring the frame cap, the total frametime on PS5 would be around 30ms (~33.33 average FPS) and 9.68ms (~103.3 average FPS) on PS6.
In this case despite the "10x RT" performance increase, the real world performance is only 3.10x that of the PS5 since there's actually not much RT going on.
On titles with heavier RT or Path Tracing of course the gap would be much bigger, but even in those cases the raster/compute portion of the frametime is still generally over 50%, so a "10x RT" increase doesn't reach anywhere near a 10x FPS increase.