[marcoseliziario]

Metals are far more important because metals provide better tools and weapons.

Better fibers give more comfort, better resistance to the elements. But, in itself, is not as much transformative as better tools and weapons.

If you went back to the distant past with modern clothes, you'd have some marginal survival advantages, but not enough for your tribe if you needed to fight for scarce resources like food.

So yes, Iron is far more relevant than flax. Because Iron gave better tools, and our history is basically the history of our tools (and weapons)