>>25650235
They had invented metallurgy. They used bronze clamps to hold the megaliths together in Puma Punku. They had animal husbandry, raising turkeys in mesoamerica, chickens in Patagonia, and Llamas in the Andes.
Buffalos aren't domesticable. Animals that can be domesticated are genetically prone to it, as has been shown in research domesticating silver foxes. There simply weren't any suitable draft animals in the Americas, other than Llamas that were too small to even ride.
If you bother to search for figures, you will find estimates of native populations prior to the Columbian era to all be >100M. The Amazon once was a vast network of cities, with thousands of cities of more than 10k inhabitants. The cultures in N. America weren't as populous as Meso and South America, but early explorers up the Mississippi reported massive cities of ~50k every few miles.
There were ~60M bison ranging across the Great Plains. They didn't need to corral and feed them to eat them. There were ~3B passenger pigeons that roamed up and down the E. coast in flocks so big they took ~3 weeks to pass over a particular point, and darkened the sky all day long. They didn't have much of a defense from predators, and it was reported you could just walk up to a tree they were feeding in and knock them down with a stick. The Carolina Parakeet, the Hickory, Elm, Chestnut, Oak and other nut crops were immense, yada yada yada.
Why slave over crops when you could just pick wild foods whenever you were hungry? However there was crop agriculture, corn, squash, beans, potatoes, tomatoes, and lots more.
You just have no idea so you scoff. Look up any of these claims and show me any link that contradicts any of it.