I think it might be a good idea to make those high sides of the vault either removable or able to be folded into the vault. Not only for what Lucky_Man describes above but also for aestectic purposes... I've seen some pictures showing the CyberTruck with a more conventional looking bed and I must admit, it does look "better." Even certain people from Georgia would probably find it more acceptable.
I don't think the Cybertruck design is pretending to cover the segment of the market of people who need to tow gooseneck trailers. While those have become more popular in recent years, they are still just a tiny part of the market, I guess 1-2% of the market. The Cybertruck is more of a mass-market truck.
If the typical gooseneck needs more clearance than that offered by the Cybertruck, it *can't* be accommodated. Here's why:
As I've been saying for a long time on this Forum, the Cybertruck will be uni-body construction and it will be shaped like an arched bridge. This is to achieve the high load capacity and rigid structure necessary for high tow ratings and to handle like a sports car. I'm afraid the typical media commentator just doesn't understand this aspect of the Cybertruck. It is not evolutionary, but revolutionary even though they can't get beyond talking about the styling.
Musk and company actually one-upped my preconceptions by making the actual body panels a more significant part of the unibody frame (exoskeleton). While current unibody SUV's and cars use some of the thin painted body panels as stressed members, their contribution to the structure is somewhat minimal. With the Cybertruck the thick stainless steel panels really ARE the frame. You are looking at part of the frame when you see the body panels. Making the sides of the bed fold inward would reduce the necessary vertical component that gives the "bridge" it's strength.
This is completely opposite the situation with traditional trucks where the sides of the bed are only to hold the cargo, nothing else. They do not contribute to the strength of the frame or the chassis rigidity and driving dynamics at all. The bed is dead weight. That is why trucks have such terrible driving dynamics. In the Cybertruck, the bed contributes to the overall structural integrity in a way that makes it impossible to cut it down in height. This truck will appeal to those who want a REAL truck, one that drives like it's hewn from a single piece of steel, not bolted together like a bunch of un-engineered disparate parts that are mostly dead weight like the current cheap jalopies are.
Ford, Chevy, and Dodge, I'm looking at you! The big three pickup makers have been building the basic structure of the pickup the same since the pickup was invented. They are ridiculous! They are incapable of change and are part of the problem. The Cybertruck will use fewer and higher quality materials to build a superior truck that costs less, lasts longer and drives like it's hewn from a single piece of metal.. No more gas tanks, fuel pumps, frame pads, exhaust hangers, transfer cases, axle U-bolts, etc. etc. etc. Detroit has been doing it all wrong and it should be highly embarrassing to them. Their customers have been enablers of this bad behavior because they didn't know there was a better way. Leave it to Elon Musk to redefine just how good a pickup truck can be. How completely embarrassing!