Apparently they rust pretty quickly if the body panels aren't meticulously maintained. Some review videos on YT that are pretty hilarious, not very practical for doing actual truck things. Plus you get that characteristic Tesla bad build quality, and recently they had a recall on all of them for the accelerator pedal sticking. It's just a novelty for tech bros and rich people who like to show off having the "newest and coolest" thing. Aside from looking like it came out of a 1990s PlayStation game.
I just looked, and evidently the body on those trucks is made from stainless steel. IF Tesla advertised them as "Made with Stainless steel, so your body will never rust", then Tesla could be looking at a massive class action lawsuit. If they were smart enough to just say, "The body is made from stainless steel", then they may be OK.