Same with Dwarf Fortress. Having significant reserves is essential to survival. There's so much weird shit that can happen to disrupt agriculture and industry. You might end up having to hide inside your fortress for years because some god awful super-monster is standing outside the gates yelling "come outside i just want to talk!" Or your miners breached a caver and now your mine is full of giant cave spiders so you have no more iron until you figure out how to deal with them.