> all of these strictly require licensed professionals to do design work Sure, but it's not clear that the licensure itself reduces accidents or abuse. Plenty

> all of these strictly require licensed professionals to do design work Sure, but it's not clear that the licensure itself reduces accidents or abuse. Plenty of licensed electricians (at least here in Ontario) are deadly incompetent. I've heard at least two accounts of electricians assuring builders or homeowners that a circuit is disconnected, and those people having an unwelcome surprise when they go to cut/remove said circuit.