In Sri Lanka (where I currently live and run a bakery business), Uber and the local competitor both charge 30% from the shop. This is in addition to a (mostly) flat fee charged to the customer for delivery, and 100% of it goes to the driver. They take cash payments as well. The amount of cash payments the driver collected is deducted from his weekly payout.
To be fair amount the margin, the drivers are paid for completing 20, 50, 100, ... deliveries, which is the bigger portion of their income.
In Indonesia, Grab and Gojek both charge 20-30%, if I'm not mistaken. In Vietnam, Grab, Gojek, and Baemin all charge about the same too. I have lived in Indonesia and Vietnam, and have seen the very same shop marking up the delivery fee into the food. I imagine this is a common practice in Asia at least.