I don't think we're too worried about wasting sand, though? What are the major costs of producing a GPU? Which of those are we worried about wasting?

I'm not going to do the homework for a Hacker News comment, but here are a few guesses:

I suspect that a lot of it is TSMC's capex for building new fabs. But since the fabs are already built, they could run them for longer. (Possibly producing different chips.)

Meanwhile, carbon emissions due to electricity use by data centers can't be taken back.

But also, much of an investment bubble popping wouldn't be about wasting resources. It would be investors' anticipated profits turning out to be a mirage - that is, investors feel poorer, but nothing material was lost.