I used DoorDash a couple of times a week for about 2 years. Thought it was an excellent service and offered a wide variety of restaurants. When I started using them they were relatively new. I finally threw in the towel and started using Postmates. One thing I liked about DoorDash was the ability to plan the delivery in advance. I could select a time even a day ahead and could rely on the order arriving on time. They have completely fallen apart. The last few months I have received so many credits for their screw ups that I can't see how they are making money.
PostMates does not offer advance ordering but they are very very reliable. I can only speak for area in Southern California. Have no idea how they fare outside of my zip code. Another thing to consider is that DoorDash expects you to add a tip when you place the order. PostMates sends an immediate email or text as soon as the order is delivered offering the option add the tip and rate your driver .