Geography pays a big role here presumably. The wheel isn't very useful if you live in the mountains and don't already have roads...

The Inka built and maintained an extensive road system. The wheel was not, as far as we know, in use in toys in Tawantinsuyu, as the grandparent comment suggested; it was in use in toys in Mexico, thousands of kilometers away, where there were no llamas. (Some North American peoples used dogs as pack animals, but I don't know if the peoples with wheels did that.)

I think it's just very difficult to make a rolling wheel. It's not like the Flintstones and the Far Side where you bang some rocks together and get a stone disc that you can then slot into your wheelbarrow (or, say, ride like a unicycle). Metals help a lot, and even bronze came fairly late to America, which didn't develop iron smelting until after Columbus. In Asia, the first (solid wood) wheels date to the Copper Age, close to the time of the domestication of the horse (and the donkey), which presumably provided much of the incentive. Those wheels are fairly fragile, and chariots had to wait for the wood-spoked wheel, which is much more complex.

But spoked wheels are expensive to build; even most of Africa didn't make much use of wheels until the colonial age, despite having iron, which the Americans lacked.

AFAIK the incas did know about the wheel, and could have presumably made them out of wood, but chose not to due to religious reasons. They venerated the sun and its shape, thus using something circular for such mundane purposes would have been tantamount to blasphemy. source: some tour guide in belize.

Why would a tour guide in Belize know anything about the Inka? Had she studied archaeology in Perú or something? I suspect you are confusing the Inka with the Mesoamerican peoples in the other hemisphere, where you were.