That sounds... plausible. If it's bottlenecking on a single thread, it looks like the 3700X should just edge out the 10900X.But your result could be the cpu. This isn't an RTX or DXR based benchmark, its Cryengine's own raytracing that they wanted to show could be done without the special hardware.
And now, having just tried pinning CPU affinity to the physical cores so I can see utilization... yeah, it's definitely got one of the cores pegged -- particularly at peak framerates.
Mystery solved, I guess...