I'm really skeptical that it's easy to automate those assembly line jobs away, or to automate mining. For one thing, robots are expensive to build. For another, while it's possible to make robots do tasks like that, there's a good chance they'll be less efficient at them than humans. And of course, if you're profit driven, given the choice between paying foreign sweatshop workers starvation wages on a high margin product and blowing billions on a risky R&D project that has a 50% chance of not working and a 50% chance of being copied by all your competitors if it does (assuming you develop something that's actually cheaper than cheap wage slave labor, which is far from a given) is pretty obvious...

that said, if you can actually build an iPhone factory that doesn't need workers, I'm believe there are many big companies willing to pay you a small fortune for that.