I was a contractor for the phone support group in a big mail-order PC vendor years ago. More than half the hardware that was swapped out like this was no-defect

I was a contractor for the phone support group in a big mail-order PC vendor years ago. More than half the hardware that was swapped out like this was no-defect-found (NDF) after being tested, for example it was a Windows problem rather than a drive problem. For a while some vendors were recycling that NDF used hardware into new equipment but I think there was a lawsuit against Dell about it. With the cheap hardware nowadays they don't even bother to ask you to send the old stuff back. Call in complaining about a mouse or keyboard problem and they'll just mail you a new one.