At least Peacock has shows that you want to watch. Netflix has a good UI but it's just a bunch of made-for-tv movies and other crap. It's just like TNT or TBS without sports.

I believe bronze and iron weapons are equally powerful, but bronze is a mixture of copper and tin (requiring two types of input). Iron is more plentiful than tin, so militaries do not need large supplies of tin if they can manipulate iron. Steel, I believe, needs much higher temperatures and purified inputs.