For a company to be as successful as OpenAI, two people won't cut it. OpenAI arguably has the best ML talent at the moment. Talent attracts talent. People come for Sutskever, Karpathy, and alike -- not for Altman or Brockman.
according to one of the researchers who left, Simon, the engineering piece is more important. and many of their best engineers leading GPT5 and ChatGPT left (Brockman, Pachocki, and Simon)