Anthropic is valued a lot because they are building AI. If they stop building AI, they are worth zero. Then they're just activists - why don't you ask Yud how many AI companies he's bought out and shut down?

Even if they could somehow cash out their entire market cap, Google's is >4x theirs. AND if they quit, their competitors' valuations go up. AND there's nothing to stop those employees from leaving and founding new AI companies.