Neither do so-called "assault weapons." You're statistically more likely to have someone beat you to death with their bare fists and feet. Do you go around worrying about that every day? I don't.
Nothing is gained by conflating unrelated topics like suicide, gang violence, domestic violence, and the occasional deranged lunatic spree killer just because they all abused the same tool to commit murder.
But if you don't muddy the water like that how are you supposed to demonize guns??
Unfortunately, most people are more interested in the simple answer than in recognizing there is no simple answer. And people are remarkably poor at recognizing that those who are muddying the waters are almost certainly arguing a false position.
Although the idea of a "Dark Age" is mostly debunked these days, the slow unraveling of the Western Roman Empire led to a real and sustained change in material conditions. Notably, population density and urbanization both decreased, along with the labor specialization that accompanies them. I'd expect most 'inventions' to happen when and where people have the most hands on time to make them! (I can't really speak to Indian and Chinese civilizations, but they have also had integration and disintegration periods)
Your first source does not support your argument that paleo-anthropology believed pottery was required for boiling. Reading just the abstract it's clear that the source is auguring for the appearance of boiling earlier than the common view that fire cracked rocks (that would have been used for boiling by placing in any water container) marked the earliest point of boiling. The Upper Paleolithic mentioned as the first appearance of fire cracked rocks, and thus assumed initial boiling, is ~5,000+ years before the appearance of pottery.
Ignoring the reference to pottery the assumption that boiling must require heated rocks is probably incorrect. I think this is a common failure mode of archeology, where evidence is preserved (cracked rocks) is favored despite obvious selection biases.
Although the laborers working on pyramids and tombs were initially mostly corvee labor, they did evolve into a more specialized and privileged class of artisans over the (very long) course of Egyptian history. The first recorded labor strike in history occurred in a village of such artisans over lack of pay.
