Yes, you can have too many CPU cores - Ampere's 192-core chips break ARM64 Linux kernel in two-socket systems, company requests higher core count support
Isn't there some kind of diminishing returns on this, where it starts to make more sense to offload things to a GPU or something instead of piling on ever more CPU cores? There has to be a lot of inefficiencies in that many interconnects.
One of their benchmark graphs is for Stable Diffusion, showing how much faster their CPU runs it than a 96 core AMD Epyc CPU. I'm like 99% sure that a GPU would run that at least 10 times faster.
GPUs are still pretty bad at handling conditional logic and are more optimized towards doing mathematical operations instead.
But you are right in the sense that people are exploring different kinds of hardware for workloads that are getting increasingly specific. We're not in a CPU vs GPU world anymore, but more like a "what kind of CPU do I need?" situation.