If you have a GPU which you've used for AI training, but that's no longer valuable, you could sell that GPU; but then you'd incur taxable revenue.
If you destroy the GPU, you can write it off as a loss, which reduces your taxable income.
Its possible you could come out ahead by selling everything off, but then you'd have to pay expensive people to manage the sell off, logistics, etc. What a mess. Easier to just destroy everything and take the write-off.
> that's no longer valuable, you could sell that GPU; but then you'd incur taxable revenue
Unless GPUs are like post-Covid used cars you're going to sell them at a loss which can be written off. Write-offs don't have to involve destroying the asset. I don't know where you got that idea.
Capital equipment is depreciated over time. By the time you're selling it off, it's pennies on the dollar and a small recoupment of cost. Paying 30% (or whatever) taxes on that small amount of income and having 70% remaining is still better than zero dollars and zero taxes.
It is a giant pain to sell off this gear if you are using in-house folks to do so. Usually not worth it, and why things end up trashed as you state. If I have a dozen 10 year old servers to get rid of - it's usually not worth anyone's time or energy to list them for $200 on ebay and figure out shipping logistics.
However, at scale the situation and numbers change - you can call in an equipment liquidator who can wheel out 500 racks full of gear at a time and you get paid for their disposal on top of it. Usually a win/win situation since you no longer have expensive people trying to figure out who to call to get rid of it, how to do data destruction properly, etc. This usually is a help to the bottom line in almost all cases I've seen, on top of it saving internal man-hours.
If you're in "failed startup being liquidated for asset value" territory, then the receiver/those in charge typically have a fiduciary duty to find the best reasonable outcome for the investors. It's rarely throwing gear with residual value in the trash. See: used Aeron chair market.