Tech companies are in an arms race to develop the first mass-produced humanoid robot, convinced they will revolutionise the way we live. For decades, we’ve been obsessed with this idea of a far-flung future where we all have a live-in robot butler to do our housework, but despite investing billions of dollars, these so-called autonomous robots still require a great deal of human intervention to do even the simplest tasks. So, why has creating a functioning humanoid proven so difficult? Choose yo