The cane torch itself was specifically suited to cave conditions in ways that other materials would not have been.

Dry cane burns steadily and relatively slowly, producing a manageable flame and a relatively small amount of smoke.

A torch made from green wood or from wet material would produce more smoke and less reliable flame.

River cane, harvested dry and bundled tight, was the optimal available material for the specific requirements of underground navigation.

Whether the ancient miners arrived at this choice through deliberate comparison or through gradual refinement over generations — trying different materials and learning what worked — is not established.

But the choice, whatever process produced it, was the right one.