What's Postmates moat? Having never used it, I don't necessarily see the 2.6b$ value in a smaller delivery app that is only really used in some areas of the US. Though I'm sure there is something I'm missing and 2.6b$ is probably less expensive than the cost of pricing Postmates out of the market especially considering it's an all stocks deal. It's just that delivery seems to be easily scalable and easy to just dump…
Drivers often work for several of these companies at the same time, and customers will use whichever one is cheapest at the time they feel like placing an order.
At the moment, with so many similar companies in the space, I don't see how any of them could become profitable, especially while being engaged in a race to the bottom on prices (because price is all that customers actually care about; the experience of a guy in a car bringing stuff to your door is pretty much the same with all of these companies).