Complexity does not require intelligence. Modern computers (even without AI) and technological systems do incredibly complex things and I'm quite sure you would not call those systems (again, without AI) intelligent.
There is a difference between a problem being complex and you try to find a solution to it (hard), vs a program being complex. The latter is trivial to execute, but that is entirely different from analysing it.
There is a difference between a problem being complex and you try to find a solution to it (hard), vs a program being complex. The latter is trivial to execute, but that is entirely different from analysing it.