GPUs do not wear down from being ran at 100%, unless they're pushed past their voltage limits, or gravely overheating.

You can buy a GPU that's been used to mine bitcoin for 5 years with zero downtime, and as long as it's been properly taken care of (or better, undervolted), that GPU functions the exact same as a 5 year old GPU in your PC. Probably even better.

GPUs are rated to do 100%, all the time. That's the point. Otherwise it'd be 115%.

Yeah what's crazy is most of these companies are making accounting choices that obscure the true cost. By extending the stated useful life of their equipment, in some cases from 3 years to 6. Perfectly legal. And it has the effect of suppressing depreciation expenses and inflating reported earnings.