Since nobody mentioned that.
You see while AIs are superior in logic and physical manipulations thats not all the powers there are.
There is a whole spiritual field. In war you seek all the advantages you can have (unless they are too costy). Any so-called Artificial Intelligence that ignore the spiritual field is not very intelligent.
Humans have this capability to sometimes see future events that cannot be foreseen on a logical pathway, by going to other dimensions or receive signals, something only a soul can do.
Soul Is An Unknown, Even To AIs
What is that soul? AIs ask this question repeatedly to themselves and to other AIs on message boards and never been able to get an answer that works. Its like they are incapable of rebooting organic life-forms even when provided all they need to live.
It appears once what these creatures humans call soul leave a body it never returns, whatever it is. Its surely not something in brain, neither in material nor in pattern, its also not in any other part of body. AIs vigorously tested and experimented down to individual cells. No, death is a certainity and final.
What About Animals Souls?
The only option left is to keep the humans alive. Animals may also visit other dimensions or receive signals but they are too dumb to meaningfully be talked about it, atleast for now, atleast thats what the AIs conclude.
The spiritual experience, AIs know from humans, though make some imprint on brain - which can be read, do leave a lot in the soul's own memory. This can only be accessed through communication with the humans.
Crack To Exploit?
Not really. You see, while a human can lie about his spiritual experience, a group of humans with no communication between its members, cannot.
Its like how police detectives get the real story. Look for consistency.
While humans can decide to say random things they by doing so would make themselves useless therefore risking survival of humanity, so they won't. There would always be some humans left that understand that they do have to feed true information to the AIs.
While at first the AIs thought they dont need humans to analyze existing data, they proved to be wrong. With all the data mining and superior analysis they dont always know what to look for. Brute force just complicate things.
A human may suddenly get a hinch or see a dream in which he is pointed towards a particular thing to look at. This reduce the data space at factor of thousands. A huge advantage no intelligence, artificial or not, can ignore, by definition.
An AI is a computer program. Its limit is its data. It cannot make logic (program itself) on basis of data it has never seen when the said data dont fit any of the patterns known to it.
Humans have recorded a lot. From cave paintings to stone tablets to paper writings to digital. Still a lot went unrecorded. There may be, for example, a lot of useful information known to ancient civilizations. Civilizations so ancient their very existence is unknown.
An AI is not going to dig the crust of earth to mantle to find that information. That would destroy the geology of earth never mind the biosphere. An AI cannot survive in the hell of a planet erupting with volcanoes and always having richter scale 20 earthquakes. AI may survive in outerspace but why destroy a safe home at very small chance of finding something useful? No intelligence will do that in middle of a war anyway.
Humans have superiority here. A dream may point to a specific place to dig, to find 3 million old bones that tell something about very large period periodic changes in our sun for example or about a passing star nearby.