> Is a delivery app that is basically a glorified basic ordering system really worth 30% of the transaction? No.

To be fair, it’s only “an ordering system” if you look purely at pick-up ordering. For deliveries, these apps are two-sided real-time resource schedulers (allocating a driver to N orders they can efficiently deliver through pickups and drop offs on a single precalculated connecting route to optimize both time and fuel consumption.) The value is in the backend software, as the very same backend software should be reusable for e.g. routing driverless taxis.