Most crypto mining outfits undervolt their cards for lower power usage. They aren't cranking them as you say they are. A dead GPU doesn't produce anything for you; cranking it up the chance that it will fail. You're better off running it an extra 4 years at a lower voltage than you are cranking it for 1.

I thought the efficiency curve for GPUs peaked before 100%. If electricity is your primary cost, driving the GPUs at lower loads saves money.

So you might end up with GPUs that spent their entire life at a steady 80% load or something.