I believe the term originated with Yahtzee during the military and tactical shooter crazy in the 2010s. It referred to games that paraded players through various spectacles and rooms full of chest high walls, until enough time had passed to call it a campaign.
You just copy, but don’t from a lot of places. If you only copy from a single thing your work is a simple derivative of that one thing. If you steal from 20 sources, that work is a masterful blend of multiple influences.