Frontier will run for more than 2 years before being replaced, but there are many more national lab type organizations than FAANG companies. If you decide to classify anything below FAANG scale as "not large", well...
And anyway, my point was merely that there are large customers going AMD.
As for the supposed contradiction: Cuda is much more than PyTorch support. There is a real breadth of proprietary C++ libraries. When I (and many others here I guess) say cuda, we mean that breadth of effort. Not just the cuda backend of pytorch. You don't have to match that breadth of effort to be competitive for very many AI applications being built higher up the stack, you only have to have a good enough ROCm backend for pytorch, and from everything I am hearing, it's getting there (if you are on Instinct, and not consumer hardware). But I don't have first hand experience.
What I have first-hand experience with is what NVIDIA tried to pitch us. They want to be the AI "platform", rather than just a hardware vendor. It all sounded like they know that their software advantage is brittle in places, hence the "platform" strategy. But they couldn't really articulate what that should mean.
I think the moat metaphor is ill-suited. This is not a situation where, if the moat is breached in some places, the castle falls. NV will have a software advantage in some domains for a long time to come. But at the same time, we are seeing that AMDs hardware can be competitive and better in domains where the software advantage matters comparatively less.