Xbox Series X is very far from the top graphics available. GTX 3090 at 35 TFLOPS is what Apple needs to compete with for Mac Pro. Those chips are reticle limited which means there's simply no room to add a CPU, let alone 32 cores. You need separate dies.
Also, Xbox uses GDDR which trades off CPU performance for GPU performance. Apple probably wouldn't do that for a Mac Pro. The high end needs separate memory so the GPU can have bandwidth and the CPU can have low latency.
Also, Xbox uses GDDR which trades off CPU performance for GPU performance. Apple probably wouldn't do that for a Mac Pro. The high end needs separate memory so the GPU can have bandwidth and the CPU can have low latency.