Conceptually what’s different than the branded delivery drivers?

• fixed wage plus tips
• already at the restaurant, so food will typically arrive hotter
• associated with the restaurant, so the brand has an incentive for drivers to do a good job
• can batch multiple deliveries from the same store, so drivers have fewer stops (doordssh etc drivers will probably hit multiple restaurants from multiple apps to keep profits high)
• usually no markup in the menu price, delivery fee is transparent

So, a lot of conceptual and practical differences beyond the couple you mentioned. I don't order from doordash etc, but I will sometimes order delivery from dominoes or something where they have their own delivery drivers. It's not hard for me to drive a couple miles to pick up my own order, which saves me money, has a better chance of having hot food, and I'm not enabling people making poor choices to work below minimum wage.

That said, I prefer ride sharing apps over taxis.