There are many parts of this
There are many parts of this article I both agree with and disagree with. I feel there are some unfair comparisons and considerations of what the Tesla is aiming to do.
Is it a truck or SUV? I'd consider it a truck, especially when you compare it to a Subaru Brat or an El Camino. Let's compare it to something more similar. Is the Chevy Avalanche a truck? Or is it an SUV worth a truck bed. Its a truck and the CybrTruck is a truck as well.
Functionality.
You say that your critiques of the cybrtruck isn't from its aesthetics but yet you criticize is design and looks over and over again. I Think Elon was more focused on the over all design of the truck through the years but I do agree that it isn't a modular design like a truck should be.
But that begs the question of what makes it a modular design? Is the Honda ridgeline not a truck because it's not a "modular" design? Or is it modular because it's the same chassis and body add the Honda Pilot? Is a new 2020 Toyota Tundra not a "modular" design or considered a truck because you can't buy it with a flatbed or cargo bed? I'll leave that question open add I don't think there is a real answer.
Also, the way you talk about "swapping" your truck beef makes it sound like it's a Lego set and anyone with an F-150 who needs to go haul some hay can go trade in the regular bed for a flatbed. Again, most companies don't install cargo boxes or flatbed, they order them like that. To say that the Tesla truck isn't customizable is being short sighted, especially since the truck won't be available for a couple of years and like vehicles now days, options can be added. Was Ram's purpose of adding the "Ram Box" (the side storage on the truck bed) to eliminate the need for cargo box truck beds? No. Same goes for comparing Tesla's truck against flatbeds or duelly's. Apple's to Apple's.
Functionality again, a lot of it comes down to opinions. Trucks have many pros and cons when it comes to functionalities. The tailgate war is all about that! Some bumpers have steps and others don't. Some trucks can have the back window rolled down and others can't. All those are different ways trucks take on functionalities. Now I agree that towing a gooseneck or a fifth wheel trailer would be difficult and maybe impossible. But I do know that people agree innovative and will find a way. Even with today's tricks, some people need an extended gooseneck adapter for their truck because the need is too small. Only time will tell what happens with that. To another point though, most people with a regular F-150 don't tow with a gooseneck or fifth wheel. Most, Not all. The majority of those that do have a heavy duty truck aka an F-250 or F-350. Even the picture you used of a truck pulling a fifth wheel was a GMC 2500 (or 3500). Do we say that all trucks should be Duelly 3500's? They are way more modular and capable so why make any other truck? As we all know, not everyone uses a truck the same. I've seen people with lifted duelly trucks and I promise you they aren't loading hay into the back of that. Most people who have an F-150 do more work around the home and maybe a few agricultural things but for the most part it's a daily driver.
Too say that, "It should be a very capable offroading SUV with good stats: 16 inches of ground clearance, a 35 degree approach angle, and a 28 degree departure angle. Those stats don’t really matter as much for trucks; their stock configurations are already more than sufficient for accessing campgrounds and hiking trails." If those stats didn't matter much then Ford wouldn't make an F-150 Raptor.
Efficiency. I laughed when you said to not take those numbers Tesla put out as they will probably change when towing or with a heavy load. Does anyone think they ate going to get what the window sticker says if they are hoping to be pulling or towing a load? I can't imagine a farmer going to go buy a new 3500 and looking at the window sticker and exclaiming, "wow! Im going to get that good of mpg while hauling my 25,000 lbs of cattle?! That's awesome!". Sorry, but most of us know that companies will do what they can to get that mpg or range top the highest level it can. Is called marketing and has been going on for way longer than Tesla had even existed.
As far as the design, I do agree that it was most likely in part of taking short cuts and being able to reduce cost in house. That I don't really agree with but who cares.
Now all that said, I'm not really a fan of the truck and design myself but I'm curious and excited to set what changes it can bring about. 250,000 others are also excluded about it. Only time will tell and see what it really brings to the table. So let's compare apples to apples and not jump to any conclusions before we sett what the production vehicle can do