[Tor3]

They knew about the wheel (as some of their children toys had them), so the explanation is easy: They did not find it effective. Completely understandable. I spent my youth walking (and carrying a lot) in nature, and not once would I have tried to use a wheeled wagon and definitely not a wheelbarrow during those excursions. If I had a draft animal I would have used it to carry stuff (as people do, with horses and dogs), not a wagon with wheels - that would have been totally impractical. And the terrain where I grew up is way easier, by several orders of magnitude, than what I could see when I visited Yucatan some years ago.

[winterbourne]

I use my wheelbarrow to do work around my mountain property all the time. We have a 4-wheel utility cart that sees a lot of service too. Their utility lies in doing work over short distances.

[Tor3]

So then we can conclude that for the type of work they did, in the area they did, they did not find it practical to use anything wheeled to help out. They knew about wheels, as already mentioned, so they obviously would have utilized wheels if that would have been effective. And they didn't, so it wasn't.