Sam Altman's return as OpenAI's chief executive will strengthen his grip on the startup and may leave the ChatGPT creator with fewer checks on his power as the company introduces technology that could upend industries, corporate governance experts and analysts said. OpenAI is bringing Altman back just days after his ouster as well as installing a revamped board that could bring sharper scrutiny to the startup at the heart of the AI boom, but strong support from investors including Microsoft may give Altman more leeway to commercialize the technology. The board fired Altman last week with little explanation and attempted to move on by naming an interim CEO twice.