The problem is in an industry like resturaunts that are low margins is that food ordering apps introduce a "too many cooks in the kitchen" problem. The restaurants add markup to the food to make a profit, this they split amongst themselves internally though there is usually very little to spare. Food delivery apps not only introduce a delivery driver into this mix that has to get paid but also a cash hungry VC startup that is burning R&D costs like there's no tomorrow.

Suddenly what you end up with is no one is making enough money to cover their costs with the current food price so each party starts adding their own fees to cover the losses and cut on other costs to save money. And then what you end up with is very expensive food and maybe one or two parties in the "kitchen" actually turn a profit.