One of the things I do all the time in my truck is reach over the wall into the back of the bed. Literally I did that a week ago to move a large box of printer filament from the back of the bed toward the front where I could get it.
In a Cybertruck, you can’t do that. If you slide something to the back of the bed, you just have to crawl into the bed to get it. I hate crawling into the bed of my truck. The grooves in the bed that guide water away from whatever you’re hauling huuuuuurt to crawl on. So, whoever designed the Cybertruck (Musk, I assume), has never actually used a pickup truck long term.
There’s also the fact that the frame of the Cybertruck is aluminum, meaning if you tow with it, it’s a matter of when, not if, whatever you’re towing (plus the part of the frame it’s attached to) will snap off your truck and continue down the highway, meeting whatever or whoever unfortunately is driving ahead of you.