Honestly, I don’t even believe it’s inefficient. There’s plenty of documented/recorded evidence of child labor around the world. Sometimes, all you really need is a pair of hands, and kids are physically capable of doing it. Countries with shitty labor laws are ripe with child labor abuse.
The UK government’s obsession with being a Big Brother is so damn frustrating. A preview of what other governments will try and become in the near future, unfortunately.