I live in San Diego, which is semi-desert, and my chain gets rusty if I don't lube it. It gets clickety if I don't lube it. It wears out the sprocket if I don't lube it. It simply is not true, in my experience, that simply because chains have o-rings that you don't need to lube the chain. There's far more to a chain-sprocket interface than just in those inner chain bearing surfaces.