My guess is that Uber won't want to sink without a fight. They might even become desperate enough to pay a living wage and find a way to make it work. In the end, the market abhors a vacuum. Someone would come along paying a living wage and filling the void. So long as there's a void to fill.
One way to balance the negotiation would be the UBI. Give people enough that they can walk away from a bad deal and the deals will get better fast.