You will out level the main quests if you do too many side quests. That's not related to difficulty or the economy.
Of course, they could have made the main quest scale in difficulty according to your level, but the last RPG that did that was Oblivion and it basically broke the game for most people.
Of course, they could have made the main quest scale in difficulty according to your level, but the last RPG that did that was Oblivion and it basically broke the game for most people.