selling loot

[The_Gun_Nut]

The big reason that you don't have technological progression that way in games, to provide an in game reason as opposed to "the GM said so," is because innovations come along through tremendous amounts of trial and error. It's only because of advanced communications in the modern world (1800+ AD) that discoveries and breakthroughs could be shared between peoples and previous works could be built upon instead of being forced to rediscover what was needed. That, and the concept of the patent allowed for inventors to share their ideas without fear of having their control and financial benefits usurped by a thousand copycats.