The Spanish thought of the Mesoamericans as absolutely terrifying foes on the battlefield - As it turns out, Spanish armor was great against obsidian weapons at making sure they didn’t pierce their armor… but so was ichcahuipilli, their own armor. You know what steel armor was terrible at?
Making sure the obsidian weapons didn’t shatter on impact and send shards straight into the unprotected necks and faces of the Spanish soldiers. You know what ichcahuipilli’s sole purpose was? To prevent obsidian from shattering in that exact pattern.
The Aztec bow, the tlahuitolli, was commonly upwards of 6 feet in length and didn’t just rival the English longbow, there are accounts from those familiar with the English longbow saying that the tlahuitolli out-ranged the English longbow. Those arrowheads shattered on impact as well.
The Aztecs in particular didn’t fight to kill - they fought to maim. They wanted captives, not dead bodies. The Spanish understood this, and it’s one of the big reasons they did everything they could to avoid actually head-on fighting with the Aztecs. They knew they would lose, due to both numbers and the fact that their armor was less effective against Mesoamerican weaponry than it was against European.
Native Americans weren’t helpless. On the battlefield, even after being decimated by disease, Native Americans often outnumbered their European enemies. It wasn’t until later on, the 1700’s and onward, that the Native militaries started to get outnumbered as their populations were destroyed by disease. And even then, they were often displaying tactics that surpassed the Americans and colonists.
The main reasons the Natives lost had nothing to do with technology and everything to do with disease, which neither side knew much about, and the greed of Americans and colonists destroying the land the Natives relied on for resources. The most obvious example of this occurs during Mahpiya Luta’s War - Red Cloud’s War - when the US gov’t traded pox-ridden blankets to the Natives in an early form of chemical warfare, and when the US gov’t put a bounty on bison skulls, which helped reduce the numbers of the American bison from over 50 millions to just under 500 in about 50 years. The other big part of that loss of numbers was the lack of tribal management and cultural knowledge, which played a big part in keeping bison numbers high.
Saying Natives couldn’t fight Europeans is just colonists rewriting history so their near-defeat at the hands of “Savages” doesn’t look so bad. The reality is that, if even just one factor - disease - hadn’t existed in the wars between Natives and Europeans, Europeans would have never gotten past the coastal regions of the Americas.