Just because humans evolved to the intellectual capabilities that we have does not mean everything is supposed to do the same.
Agreed.
You are probably already aware, but our ancestors lived under very different conditions than their arboreal ancestors, conditions that allowed the mutations leading to increased intelligence to result in increased biological fitness and a survival advantage.
North and South America converged creating the isthmus of Panama eons ago altering the ocean currents, changing weather patterns, and causing some of the jungles of Africa to transform into relatively treeless savanna. This forced the arboreal apes in those regions to come down from the trees and trade their limb-to-limb swinging, leaf and nut eating lives into a life of cooperative hunting for meat while running on the ground.
The articulate, grasping hands needed for brachiating through the canopy were freed for weapon making and deployment. Identical mutations leading to increased cranial capacity and intelligence would not give the arboreal apes the competitive advantages that it conferred upon their terrestrial cousins given their new lives, and certainly would not be worth the high cost of possessing and operating brains that consumed such a large percentage of the animal's oxygen and calorie intake, and exposed it to the dangers of difficult deliveries of large-brained babies.
Man developed a unique form of intelligence - intellect, or the ability to ponder and communicate using symbols such as words. If intelligence is defined as the ability to identify and solve problems, something many of the lower beasts such as my dogs also do, and intellect is defined as the ability to do so with language and mathematics, we must consider under which circumstances that symbol using ability confers a competitive advantage even after the biological costs are subtracted out.
If worms or fish could somehow evolve such thinking skills, would it benefit them overall given their lack of hands with opposable thumbs and the absence of the fine vision primates developed before descending from the trees? Probably not, which is probably why we don't see such creatures possessing human intellect.
It is our unique heritage and the circumstances of our ancestors' lives that are likely the reason that man went in a unique direction in evolution. If the increased intelligence can't be put to use immediately as was likely the case for our hominin ancestors, then it won't be selected for.
For me, this is a plausible explanation for why only humanity has newspapers.