If artificial intelligence is exactly the same as intelligence, then wouldn't we just call that intelligence? People won't use words if there is no useful meaning conveyed. I am not sure you have made clear what useful information is found within "artificial".
> I'd assumed "and not natural / created" was a given
And, really, what does it mean to be not natural or created in this context anyway? The dictionary definition is kind of hand wavy to begin with, leaving whether humans with intelligence are natural or created up to interpretation.