For productive generative AI, all that's needed is for what it produces to be non-ownable along with anything incorporating it. For generative AI fitting into an internal supporting labor role a different solution would have to be found, I'm not sure what but a nuclear option to strip away property rights from anything touching it would probably be the simplest and strongest (also the idea that "the servers running the chatbot are free you can just take them home I have hundreds of them" being real and legal is very funny).

I've come to the conclusion that it's impossible to stop all the negative effects of AI, so policy responses should be focused on stopping the most harmful uses that can be stopped, and within that framework corporate control and ownership of it is an existential threat in a way that all the harm that would come from AI proliferation is not.