Charisma is a euphemism for people starting to see dollar signs when they get close to him. The better you are connected, the more people want to connect with you, and Altman seems to have driven this to an exreme in SV, and the broader policy/tech world thanks to OpenAI. If you look at who is (probably) going to leave with him, it is mostly former ycombinator people or people clearly drawn to OAI through his connections.