Fidji Simo, chief executive officer of Instacart Inc., speaks during a Bloomberg Studio 1.0 interview in San Francisco, California, U.S., on Thursday, March 3, 2022.David Paul Morris | Bloomberg | Getty ImagesFidji Simo, OpenAI's product and business chief, on Thursday announced she is stepping down from her role at the artificial intelligence company to focus on recovery after a "severe exacerbation of a chronic illness."Simo was diagnosed with Postural Orthostatic Tachycardia Syndrome, or POTS, in 2019, and said she's been spending "countless hours in doctors' offices, dealing with symptoms, treatments, insurance, uncertainty, and all the invisible work that comes with being a patient."She stepped away from OpenAI in April for a medical leave. OpenAI President Greg Brockman took over pro