Facebook boss Mark Zuckerberg's metaverse push has so far cost his company $21 billion, with little to show for in terms of real results, according to a recent Bloomberg opinion piece. For the massive amount of money spent on developing a metaverse, Zuckerberg and Facebook-owner Meta have only managed to sell some 20 million units of the Quest virtual reality (VR) headset since 2019, Bloomberg technology columnist Dave Lee said in the piece....