dub DOES involve "dubbing" tho! - traditionally it was process of blending multiple reggae rhythm tracks together using strong EQ cuts and sending parts of the tracks to outboard effects with the aux sends. it was a way to perform using just a mixer and really opened a lot of doors towards performing modern electronic music I'm not an expert on this at all but it is super interesting reading to me IMO
yeah, the name did originate that way though (especially in regards to chip stuff) the modern genre has expanded well beyond that because there are lots of new ways to achieve similar results