Warren Buffett's biographer says he's 'literally not replaceable' as Berkshire Hathaway enters a new era
1. Warren Buffett plans to resign as CEO of Berkshire Hathaway this year. 2. Buffett's retirement raises concerns about the company's future leadership. 3. His successor, Greg Abel, faces challenges in maintaining company performance. 4. Berkshire's diversified business model is seen as a stabilizing factor. 5. The market's reaction to Buffett's departure remains unpredictable.