Older Intel iGPUs used to support GVT-g, they got rid of that in the newer models.

SR-IOV ("true" GPU partitioning) is targeted at the Arc Pro/DC GPUs only, not the desktop variants.

That leaves Intel in the same boat as the others these days: you can either pass the whole GPU through or buy a non-consumer variant for proper hardware virtualization (or try to hack it).

From what I recall they started adding SR-IOV support to Xeon iGPUs. Among the ARC GPUs you still need a PRO model.

Yes, I think Intel did offer that, but I recall hearing their software wasn't very good.