Iron technology was perfected by the

Iron Technology was improved during the Warren States period in China, from 776 BC to 221 BC. This was also a period known as the Iron age, as regional lords in China sought to improve their iron manufacturing techniques in order to elaborate better weapons that will bring them a competitive edge against their pairs.

During this time, meteoric iron was replaced with a new type of iron nicknamed "Pig Iron", which was easier to work with.

i think its the outcome of people's preferences.

answer; the period of time known as the middle ages;