Yeah that's not how it works in practice in a datacenter with the latest GPUs, they are basically perishable goods.

You don't run your gaming PC 24/7.

No, you're fundamentally wrong. There's the regular wear & tear of GPUs that all have varying levels of quality, you'll have blown capacitors (just as you do with any piece of hardware), but running in a datacenter does not damage them more. If anything, they're better taken care of and will last longer. However, since instead of having one 5090 in a computer somewhere, you have a million of them. A 1% failure rate quickly makes a big number. My example included mining bitcoin because, just like datacenters, they were running in massive farms of thousands of devices. We have the proof and the numbers, running at full load with proper cooling and no over voltage does not damage hardware.

The only reason they're "perishable" is because of the GPU arms race, where renewing them every 5 years is likely to be worth the investment for the gains you make in power efficiency.

Do you think Google has a pile of millions of older TPUs they threw out because they all failed, when chips are basically impossible to recycle ? No, they keep using them, they're serving your nanobanana prompts.