One thing is that the companies are holding on because of competitive advantage, and I think another is that AI is such a politically polarizing topic that actually being open about everything is risky for the companies, wanting to avoid controversy.
I have no idea if Andrej "sold out" but perhaps he realizes that if he wants to work on the cutting edge alongside talented people, with a seemingly endless budget, Anthropic is a good choice.
I chose my employers for the same reason; the compensation was secondary.
There's some poetry there that I am unable to capture with words.
When I left MS, a full Windows build was about 18M LOC. The fact that 18 million lines of code, written by tens of thousands of engineers, worked at all was a mini miracle.
With regard to compensation: like Karpathy, I had already earned enough to be comfortable for the rest of my life. Once money stopped being the primary driver, I was able to focus on what made me happy. Building things, even if you don't like them, brought me happiness and fulfillment. I hope Andrej finds the same at Anthropic.