You forgot the ever important asterisk of “yet”.
Artificial General Intelligence (“Real AI”) is all but guaranteed to be possible. Because that’s what humans are. Get a deep enough understanding of humans, and you will be able to replicate what makes us think.
Barring that, there are other avenues for AGI. LLMs aren’t one of them, to be clear.
Any element can be made into a state you can eat, drink, or breathe. Doesn’t mean you’ll survive the attempt, nor even properly get to attempt it.