There is a use for older GPUs, but the chips do have reliability issues. Turns out running chips hard 24/7 causes them to burn out. So it’s less will they be “useful” a while from now but more will they still work.
Folks are leaning it’s like these LED light bulbs that say they’ll last 15 years but after 2 years they start flaking out at a high rate.
Separately, the broader point is still directionally correct. We’re still using fiber from the .com network infra implosion today and will for a long time. The deprecation cycle is incredibly long. The increasing reports of GPUs sitting on shelves because there aren’t data center to power them is very concerning considering all the high interest debt being used to buy what is ultimately a rapidly depreciating asset. Financially, that’s a disaster waiting to happen.