Nvidia and AMD both have their own unified memory laptop SOCs, now. Apple Silicon's GPU is relatively weak, it's one of the less-efficient ways to use 100w for compute.

Even the fastest Apple Silicon chips like the M5 Max and the M3 Ultra still put up worse GPU compute performance than last-gen laptop RTX 4080 chips. And they don't scale, the largest M3 Ultra cluster you can configure is still ~2,000x smaller than a DGX SuperPOD. There's a reason Apple discontinued their rackmount hardware, there's very little demand for Apple Silicon in the datacenter.