There's a massive amount of evidence that consciousness occurs in the brain. If one were to propose that it's just a correlation then some kind of convincing argument would need to be made about how and why.

I read GP comment as "there is no evidence that everything having a brain is conscious (and vice versa)", not as "the place where the individual's consciousness operates is the brain".

The former could be applied to whatever LLM is the hype of the day.

It's interesting though that the only consciousness that I'm sure of exists is my own. Anybody else's is just somehing I'm assuming. You can measure intelligence, but not consciousness.

True, and there is also plenty of evidence which snows how neuronal degradation in some pathways leads to losing aspects of consciousness.