(Bloomberg) -- The relentless erosion in Rivian Automotive Inc.’s share price is revealing an ugly truth: Investors have little faith left in the ability of the Amazon.com Inc.-backed company to compete in a crowded electric-vehicle market.Most Read from BloombergJPMorgan to Acquire Failed Regional Bank First RepublicPeak Oil Spells Trouble for ConsumersBuffett Will Beat the Market as Recession Looms, Investors SayFirst Republic Talks Extend Into Night After Banks Place BidsJerome Powell Could F