This is just about efficiency. Postal (including UPS / FedEx) can plan the route ahead, stack parcels with as little space as possible, and deliver hundreds of packages in a day. UberEats doesn’t know when will order show up, doesnt know when will order be ready, it can deliver maybe 2 - 3 orders in a row, the route planning is just in time.
Tell me how is this only explainable by socialized system.
but if cheesecake factory hired him and supported him to make this discovery, you would look at the menu differently.