But what about the GPUs that are considered defective for corporate and enterprise use, but perfect for personal use...say like A100s that maybe having ECC issues but I can live with that

We ask any seller to post the condition and testing reports for the hardware they sell, so there is no info asymmetry. As long as there is a willing buyer and a willing seller at the conditions specified, transaction goes through! We deal with A100s all the time.

Nice thing about these chips is that they have built in software that allows you to see the condition. The secondary market also supports the circular economy, most of these servers are proving to be useful longer than what the market initially thought. There is always a case to go with used equipment instead of new ones.