what's your alternative theory?

Whats your alternative theory?

So here is a map of the valley of Mexico, before Lake Texcoco was drained. As you can see, there are flat areas, especially along the lakeshore, but the valley is lined with hills and there are even hills between major population centers. This isn't to say there are no flat areas, but elevation is a major concern for any significant travel distance.

Here is a map of the Incan Empire. Notice the terrain between major population centers like Cuzco and La Paz or Lima? Again, there are places where a wheeled cart would have helped, but overall the land is quite mountainous.

There's two* main areas in the Americas that had dense urban cultures, Mesoamerica and Peru. Both areas are generally mountainous, with sharp changes in elevation, where wheels wouldn't be bery useful. In addition, Mesoamerica didn't have any large domesticated animals to pull carts, and Peru had llamas, which are fairly dainty and weak. Between the lack of draft animals and the steep terrain, there just wasn't a good use for the wheel.

*there was also the Mississppians, but we don't know a lot about their culture. One can imagine the lack of draft animals was an issue, even if the terrain was flatter.