To preface: I find it extremely unlikely that this will ever see widespread consumer adoption if any at all. If it is indeed feasible to transmit power via ultrasound, there are additional hurdles to overcome. It will likely be high cost and reliability is an issue, and there is the question of limited appeal or application space. Everything I have that needs power has an outlet or easily available place to charge. I'm suprised they were able to trick not just people like Cuban into investing but also Marissa Meyer?

I can however see some use cases for this tech but just not for your average consumer. I bet someone could invent a surgical instrument that needs power wirelessly or there could be some equivalently niche use case for this kind of tech.