If we know someone, doesn't that mean that we know something about their personality, i.e., how they are likely to behave in various circumstances? Doesn't that imply a degree of predictability? To the extent behavior is predictable, doesn't that mean that it follows rules? If so, doesn't having an identifiable personality imply some lack of free will?
If rational behavior is something to strive for, doesn't that imply predictability, hence a lack of free will?
If someone exhibited free will, wouldn't their behavior be random? Doesn't this imply behavior that is unrelated to circumstances? If so, free will would seem to imply remarkably unproductive behavior with no survival value.
Perhaps free will is an illusion.
That is not to say that conciousness is an illusion. Conciousness and free will are entirely different things.