The Tesla Cybertruck was supposed to be the future. Unveiled in a now-infamous 2019 event where its supposedly “bulletproof” windows shattered on stage, the sci-fi pickup, with its polarizing stainless-steel design, was hyped by CEO Elon Musk as an indestructible vehicle that would completely disrupt the lucrative truck market. Today, that future looks like a commercial flop. Prices for used Cybertrucks are in a freefall, a stunning collapse that has become the most visible symbol of the deep and growing crisis at Tesla. According to new data from the auto marketplace CarGurus, the average price of a used Cybertruck has...