>>96367668

Easy. Material Scarcity.

A "dark fantasy" much like reality where either because of war, natural disaster, or unknowable otherworldly force, the basic materials (food, water, shelter or the material to build shelter) are severely depleted.

Base it on ancient Greek/Rome, where due to the constant conflicts and empire expansion, the land is salted and ruined.

Or come up with your own reasons.

Its hard to adventure when your moral choices are dictated by hunger, thirst, or exposure to the wilderness.