I'm generally in agreement with all your points, but I would propose that it's not _only_ the hardware that is serving as NVIDIA's moat.

They have poured an enormous amount of time and effort into CUDA and its related libraries. All of that work—in addition to the hardware—is what makes their moat deep and wide. If AMD and/or others invest similarly in ROCm, that will be very telling. Oh, and the work that the Mojo folks are doing is also very interesting; I could also see that as a looming threat for NVIDIA!