The arguments I could see revolve around creating some sort of moat. There's an extremely shallow one in "I already have A on my phone, it would be three minut

The arguments I could see revolve around creating some sort of moat. There's an extremely shallow one in "I already have A on my phone, it would be three minutes of clicking and enterring my payment and delivery info to try someone else." If you could give-away-the-store to get sufficient market share-- maybe like 70-80% or more-- you might be able to start leveraging the restaurants, demanding exclusivity (or offering some cross-promotional incentive in exchange for it) to keep competitors from emerging. Or maybe this was an offshoot of the Uber endgame hypothesis: if you can survive long enough to get to driverless vehicles, you can own the largest fleet and actually get your hands on economies of scale.