Maybe, maybe not. Nvidia P40's GPUs were released 8 years ago, they are hot. Prices have doubled in the last year. Nothing will be written off in 6 years. Folks will be using A100 15 years from now. 7 yrs old V100 32gb GPU cards are still going for $1500 on ebay. We are more likely to invent a more efficient software architecture than invent a new type of better hardware and replace everything that exists.
And more importantly, the GPU is the most replaceable part of the datacenter infrastructure. Power, buildings, cooling, security, cabling, internet backbone connectivity, etc. are the harder to swap pieces that require time to build out.
Right but that’s just digital infrastructure, and of course that will have positive side effects, no matter what role AI has in the future. Rail otoh is the infrastructure.