The problem with the Nvidia replacement goal of big tech is that they don't have an ARM-like organization to design cores for them. Big tech use their own ARM CPUs because they use stock ARM core designs and its ISA. The hardwork was already done for big tech.
Big tech must design their own GPUs. From the looks of it, it's much harder to do it on your own than license cores from ARM.
https://www.businessinsider.com/amazon-nvidia-aws-ai-chip-do...