My point is that all of these are "simple" problems. Oh the truck will identify a plastic bag. Oh the truck will have a cargo manifest and drive accordingly.
But these are all new technologies. Our visual recognition libraries are nowhere near ideal. I said this elsewhere but I will say it here too - our best of the best software can't tell a zebra and a sofa in a zebra print apart. I'm pretty sure that all that LIDAR is seeing is a spherical object on the road, it has no idea what it is.
The same with the cargo manifest - it sounds simple, but no one has a system like this. It would need to be made and implemented, and it takes time and effort - I'm not saying that it's impossible, far from it, but it's one more obstacle to overcome to make this possible.