Note that you've gone in the space of a couple of sentences from "I don't understand this," to "This is dumb." I recommend going with one or the other; mixing them is trouble.
The use of tech here is in the ordering, inventory management, and delivery. In particular, the instant gratification. Before the mobile web, this would have been expensive and difficult. You'd need paper catalogs, phone center operators, dispatchers, trained drivers, and a lot of stock-keeping magic. Plus some very smart supply chain management. Now you need some software and off-the-shelf smartphones and you can cheaply test a whole product idea.
Now they're apparently betting that the cost per delivery can be kept low enough that they can bring you fancy bread and baked goods at a decent margin. On it's own, I'd call it a mildly interesting proposition.
The question for me is what they're planning next. Amazon started as just books, Netflix as mail-order DVDs, Square as a weird dongle that plugged into your phone's audio jack. All began with something basic, something many people laughed at. But they were all playing bigger games.