McKinsey & Co.’s consultants are increasingly drafting proposals and making PowerPoint slides using the firm’s generative artificial intelligence platform, which has developed enough to take over at least some of the tasks typically performed by junior employees.While employees have access to the likes of OpenAI’s ChatGPT, they can only input confidential client data into Lilli, the proprietary platform aggregating McKinsey’s knowledge base, according to Kate Smaje, the company’s global leader o...