…damn it, I have way too many spare power cords to even count. And a good portion of those have, apparently, never been used before (with their original twist-ties untouched). Including quite a few types with CEE 7/7 and BS 1363 plugs, that came with equipment imported by someone else…
Clearly, this situation is responsible for a lot of wasted PVC and copper — though, to be fair, it's not as though the amount of equipment going to waste isn't even worse. That aside, the fact that the length of the bundled cables is chosen by the manufacturer — not the user — is going to leave many users with cables that are either excessively long, or too short, for their setup. After all, isn't the whole point of detachable cables (aside from making it easy to replace a damaged one) that you can choose those you need?
What's really weird is when equipment includes some of the required cords, but not others, or when an interconnect for an old outdated interface is included but not one for a modern interface (such as a DVR that came with a composite cable, but no HDMI cable).