> What happened with cigarettes?

We established a comprehensive set of data that established correlation with a huge number of illnesses including lung cancer, to the point that nearly all qualified medical professionals agreed the relationship was causal.

> There must be a prominent & visible warning

I have no problem with that. I’m a little surprised that ChatGPT et al don’t put some notice at the start of every new chat, purely as a CYA.

I’m not sure exactly what that warning should say, and I don’t think I’d put what you proposed, but I would be on board with warnings.