This is a misunderstanding of what essential complexity is.

If it could be subdivided into its own small, manageable piece, then we wouldn't really have a problem as human teams either.

But the thing is, composing functions can lead to significantly higher complexity than the individual pieces themselves have -- and in the same vein, a complex problem may not be nicely subdivisible, there is a fix, essential complexity to it, on a foundational, mathematical level.