So when the load shifts, how does that get addressed? What does the truck do if a chain or strap fails because of load shift or simple wear/tear? How can it even detect that? Just cinching them down means you'll crank the snot out of them and damage some loads. It's less viable and such an easy solution as you think.
Where automated trucking will shine is hub/spoke operations. Automated trucks honestly will hit Old Dominion, YRC, Reddaway, Fedex/UPS/ETC, really hard on the backbone side. Point to point shipping, and final mile, not so much. It's most feasible for them because they would easily be able to configure a vehicle reception/departure checkpoint where the power units could be disconnected and reconnected by yard personnel.
Even that fantastically automated beer load being bragged about, had human requirements on both ends.
Drop-hook type operations at big DC's would still be complicated plus require human input above/beyond what the customer is going to accept, as they would be confirming locked kingpins, connecting air lines, etc. I don't see Lowes or Home Depot accepting responsibility at ALL for having automated trucks deliver to their facility, and having to do connections/etc. They now take on additional legal responsibility if something fails on the road, and they also are accepting additional work for their hostlers as the Auto-Drop point wouldn't be where the trailers actually need to go, as nothing has demonstrated they can even back a trailer up... which means you need a pull thru point to drop a load, then someone to move the power unit over to the empty and/or connect it to the empty. The Consignee isn't going to be cool with hopping in some other companies trucks nor with doing the hookups. Sure, you can get automated arms to hook up with, but how well are those going to handle a 90 degree blindside extension?
Envision every mega, Swift, Knight, CR Eng, Bla de bla going automated right now.
Auto-drive systems across the board still can't deal with stoplights and stopsigns, partially due to regulatory controls, partially due to system limitations. Throw in the additional maneuvers required for running a truck on city streets, and they have a lot of work to do.