“And the wheel. Wonderful thing, that.”
The “wheel” argument applied to intelligence level is absolutely ignorant. They knew about the wheel, They had game balls hoop games that incorporated the physics of the wheel. They just didn’t need it so why use it? It is very impractical to live nomadic and have to “rely” on the wheel along with the roads, beasts of burden to feed and water, and infrastructure to accommodate the wheel.
Example South America... With no beasts of burden larger than a Llama or Alpaca, why build road systems across the Andes mountains to accommodate the wheel? All they needed were roads big enough for sure footed mountain pack beasts. The Andes were not and are STILL not very friendly to vehicles depending on the wheel.
In survival there is a fine line between the profit and loss of calories gathered and calories burned. Logic dictates you do not waste calories on physical effort you do not really need.
Yes, much like Africa, ‘they’ needed a domesticated animal source to be able use a wheel, or ‘ride’. Zebra vs. horse argument and all.