Really Shitty Copper

Yeah, but you can cast bronze fairly easily, while casting iron is more of an AD technology. Early modern, if you're European. Traditionally you don't even let it melt while smelting.

Blacksmithing with wrought iron is way harder than working with something like bronze. There's slag in it either just from oxidising or from the solid smelting (bloomery) process, and so it has a kind of "grain" that builds up over time. If you don't account for that your sword or plough will be trash.

It also rusts, is softer than bronze (even as most steels) and not necessarily stronger. The only real advantage is that it's common and doesn't require a trade network for rare elements, which is why it didn't fully catch on in the Near Eastern world until after the bronze age collapse.