One of the comments reads : Actually, we will probably never figure out, was it man or woman. but I thought this comment of the professor was an interesting eye opener. https://mastodonapp.uk/@MarkHoltom/112070436760917344
70 years is not enough to fully industrialize a society
Russia, China
Also, I imagine industry in general becomes significantly easier when you have people that can summon construction projects out of the ground or weld with their bare hands.
Also, society isn't industrialised. One city state within society is industrialised.
Also, the fire nation was already undergoing industrialisation at the time of ATLA.