As I understand it, Anthropic exists in part as a quirk of how Dario Amodei's experience at OpenAI went. In the world where Musk controls OpenAI, I don't think you can assume Anthropic splinters off the same way (for overdetermined reasons! I'm not saying Musk is a better manager.)

Hmm, my understanding is that Dario split over insufficient focus on safety at OpenAI (which, admittedly, could just be the PR-friendly reason) -- something that Elon is also clearly not big on.

Safety not only seems to be an anti-priority at xAI given what we've seen come out of it, even at OpenAI Elon seemed not that concerned with safety, leading to that entertaining incident with a "golden jackass" trophy: https://xcancel.com/abc7newsbayarea/status/20546984193823543...

Almost certainly Dario would still have split from under Elon too, but also very likely that Elon would have immediately thrown a barrage of IP / NDA / trade secret / non-compete violation lawsuits to cripple Anthropic and keep it from reaching the frontier.