???
Erm, well, aside from the fact that you seem to be lumping several different peoples together...
Figure 1: The Mayans built large paved roads between ancient cities that still exist today and can be traveled on. Other peoples would have had well-traveled roads as well.
Figure 2: This is the Mayan writing system. The Mexica had a similar system, and the Olmec probably had one as well, though no evidence of such has turned up yet.
Agriculture was well-developed within Aztec society. It was probably more efficient and less work than US agriculture today, as a matter of fact. At least they wouldn't be caught having to turn all the excess corn into liquor in a desperate attempt to not go bankrupt as the surplus in the market causes prices to drop.
Important war captives were primarily used as sacrifices. Babies were not used. For example, 'los danzantes' (the dancers) are a large group of carvings representing war captives in various states of sacrifice, and each have a specific name written in hieroglyphics. Kings and nobility would have been much more likely to be sacrificed than any other person. They would have also been forced to participate (and lose) in the ritual ball games where the losers were killed.
The Europeans, of course, eventually swooped in, spread their plagues, took the gold they saw, burned nearly all the manuscripts in an attempt to exorcise the devil from Mesoamerica, converted or enslaved or killed the natives, and left behind the broken remnants of a people that most today consider vicious, baby-slaughtering, bloody-minded, uncivilized inferior savages with no proper form of society to be seen, who only know how to do war whoops and say things like, "Me big chief!" while beating their chests when they're not dismembering innocent children to appease their barbarian gods.