Why do they do these tips?! Why not charge a total and pay all expenses and people from that? I don't understand why the complicated setup and all the fuss that comes from it. Seems like they create problems for themselves out of nothing.
These are all dark patterns that try to hide the actual cost.
If doordash was upfront, saying “your total extra charge from doordash for delivering this to you is $25” instead of “$3.99 delivery; $12.57 service charge; $10 tip for driver” you might be more likely to realize how damn expensive the service is and pick up your own food.