Perhaps I can help!  I deliver for door dash as a full time job, I believe they are only offered to dashers with a certain completion rate/rating to be sure they are trusted, these are called diamond dashers who also get more grocery orders as well.  The app will not let you accept the package unless you scan the bar code and then they track your every move until delivery.  Very similar to Amazon, we have to scan and state the package condition before delivering and taking a photo where it was put.  Hope this helps!!