Is there a big difference in principle between that and the "shared video memory" that has long existed on cheap x86 machines? …or is it just that the latter h

Is there a big difference in principle between that and the "shared video memory" that has long existed on cheap x86 machines? …or is it just that the latter had a way too weak iGPU and not enough RAM for AI purposes, whereas the bigger ARM MACs have more GPU power and enough RAM (more than most affordable discrete graphic cards) so that they are usable for some AI models?