Food delivery is not new. The new thing are the web interfaces. Now people don't need to visit shops to learn about new things. People can shop delivered goods all the time. This allows to drive down delivery costs with scale.
Additionally, online shops streamline the ordering process. No person is needed to note down orders.
Additionally, self-driving cars and robots will eliminate the cost of the last mile. Like Uber, whoever owns the market when the robots will go life will rake in huge profits.