XBSX has 8 Zen 2 cores running at up to 3.8 GHz. They have an R9 3900X which is 12 Zen 2 cores running at up to 4.6 GHz. Pretty obvious winner there. GPU performance is a little trickier, given that we don't have independent results for RDNA2 yet, and it's hard to say how the consoles' power/thermal envelopes might effect performance relative to desktop. Based on AMD's results for the RX 6800, it's a bit better than a 2080 Ti. Based on specs, the 6800 is ~15% better than the XBSX GPU. So on paper we could say the 2080 Ti and XBSX GPU are roughly equivalent (if we could do a real world apples to apples comparison, I'd expect the 2080 Ti to win). Their PC has 11GB of VRAM and 16 GB of system RAM, XBSX has 16GB of RAM in total that must be split between CPU and GPU.
The XBSX can run CoD:CW at 120 fps, or 4K, or with RT. Not all at the same time. And both 120 fps and RT also involve using dynamic resolution/upsampling techniques to get better performance by rendering at a lower resolution. If we allow for upsampling, then a 2080 Ti is indeed capable of running CoD:CW at 4K and RT at 60+ fps (using DLSS). Or 120+ FPS at native 1080p with RT off.