I think the melting point had something to do with it as well, along with lack of sufficient energy sources and ore supplies. Copper and iron (meteoritic iron; analogous to the bottle in “The Gods Must Be Crazy”) were used side by side back to the edge of the so-called Stone Age, but bronze is more complicated, that is, it was difficult to discover just how to do it.
Here’s a ‘civilizational will’ bump back to the top.
Live it and defend it or lose it.