I think the appeal is that you probably don't need a huge CPU for a lot of workloads-- just something to run an OS, handle talking to the outside world, and configure the GPU/NPU complexes.
I could imagine a something like a Quadro card that had a small RISC-V core built in as a freestanding device, no motherboard needed. Even if the CPU ran like a Core 2 Duo, that would be sufficient for purpose, but it will be a lot easier to license an appropriate RISC-V core than an x86 one.