The silicon gates in GPUs just don’t wear out like that, not at that timescale. The only thing that sort of does is SSDs (and that’s a write limit, which has existed for decades, not a new thing).
https://duckduckgo.com/?t=ffab&q=gpu+lifespan&ia=web
You'll need to scroll past the ones talking about obsolescence versus failure. Toss in 'data center' if you like.
You'll see a range of numbers -- including some lower than I cited -- but it's all in that ballpark.
since electromigration is basically a matter of long, high-current interconnect, I guess I have been assuming it's merely designed around. By, for instance, having hundreds of power and ground pins, implying quite a robust on-chip distribution mesh, rather than a few high-current runs.
But it someone is running an LLM 24 hours a day, might not go for as long.
We are flying blind, both on those claiming short life span and those who are not.