GGG is keen about the idea that Path of Exile is above all an economy-based game. The decision to exclude gold from the overall game was made prior to open beta, and trading was likely to carry risks. Solo Self-Found, a player-made playstyle that dedicated to finding and POE Trade crafting your individual gear, originated as being a way for folks to avoid suffering the trouble of trading with other sites. It was small peanuts until that it was finally built into in 2017, many POE Currency years after launch, and also the game is explicitly not balanced around it.