While it's true that droids are found in even poor parts of the galaxy, those droids are clearly well worn, well used, and are probably quite old, probably several generations behind the latest in droid tech on wealthier worlds. We also don't see many of them in any one place. outside of the droid army during the Clone Wars. So while they're definitely around, I'd argue that they're not exactly everywhere.
Something else that goes against droids being used for the production of whatever they're making on Narkina is that the Empire hasn't shown to be particularly big on using droids outside of some specific uses like probe droids and interrogation droids. We don't see many, if any droids on Star Destroyers, we only see 1 protocol droid and some mouse droids on the Death Star, and we've seen 0 doids in the ISB HQ.