That's the thing though. Software is cheap with AI, but Nvidia has Cuda. If software doesn't matter anymore (it does) because it's so cheap now, then Nvidia's moat evaporates to IBM's Spyre. In reality "just a little bit of software" has inertia and cannot be dislodged quickly, quietly, or easily. cf Microsoft.
As for CUDA: I think CUDA is a formidable moat but I also think that that is precisely the kind of thing where the likes of IBM could (if they really wanted to) make things happen. They're already in the space with Redhat and they have ample knowledge about drivers and low level code. Putting together a team that either makes a drop-in replacement or alternatively, that starts supporting their custom hardware for the big players in the inference space (VLLM, llama.cpp and Torch) would make all the difference. They'd have to keep doing it though, even if the initial results were lower than expected because that market is not going to turn on a dime.