Amazon CEO Andy Jassy said gen AI assistant Amazon Q saved thousands of work hours.Mike Blake/ReutersAmazon CEO Andy Jassy said its AI assistant, Amazon Q, drastically reduced software upgrade times.Jassy said that's saved the equivalent of thousands of years of work, plus millions of dollars.AI tools can enhance productivity across industries, including marketing and sales.Generative AI has some workers worried that it'll take their jobs. But b…