Not frightening. Intelligence is well beyond the capabilities of any computers existing today and probably for the next couple of hundred years at least.
We can mimic intelligence but true intelligence needs sensory input, desire, intuition, fear, love, hate, etc.
Have you read the BBC’s article The Man With Two Hearts?
Video at link on post #2 has a comment on that.
What desire/pleasure/pain actually is is a major mystery but it seems like even plants and microbes experience it somehow, else why do they bother with what they do? One of the strongest desires in the universe is a negative electron seeking out a positive mate, so whatever desire is, electronic thinking machines probably already have some form of it.