I still can't reconcile how they didn't use the wheel for transportation. The explanations of lack of draft animals and unsuitable terrain aren't great. Not even a wheelbarrow?

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.

Premodernist has a good video on why certain societies didn't develop wheelbarrows: https://www.youtube.com/watch?v=BRnwg3dpboc

It mostly boils down to us overestimating the utility of wheelbarrows from the perspective of our modern, cushy lives. Ancient humans are not dumb and have as much desire to avoid labor as we do.