At that point, the restaurant is left with 100% liability for the cost of the raw ingredients and of making the food. The courier can leave (wasting their own

At that point, the restaurant is left with 100% liability for the cost of the raw ingredients and of making the food. The courier can leave (wasting their own gas money), but the 3rd-party delivery service is entirely removed from the situation (they lose nothing by not paying, as the customer and their driver will almost definitely blame the restaurant). It is currently being addressed in that way, but it is ruining the reputations of these local restaurants, and burning through their cash.