Don't forget that they had canning technology in the first Mistborn trilogy. Canned food is huge, without it poeple in real life would not have progressed geographically wise as fast as they did, and geographic expansion led to new discoveries of resources such as various medicines (like aspirin), new cultures and a great expansion in trade.
Anyways, it was my impression that the major cities were relatively advanced, being at a later date level of technology, and the frontier towns would be more primitive.