> Then again, Bill Gates thinks it may have plateaued

He didn't say AI may have plateaued. He said the OpenAI may have reached the limit of the current design. Very different thing. From your link below:

He anticipates a stagnation in development initially. The billionaire said that, with GPT-4, the company has reached a limit, and he does not feel that GPT-5 will be better than its predecessor.