When a system grows and evolves, its complexity increases. Take a look at evolution in our biosphere to realize that this is true. If you want to accomplish more you must become more complex. This means two things: structure and entropy. Structure is what defines functionality, entropy is what allows a system to react in a creative and novel way to a changing and possibly harsh environment. In biology this is adaptation. When you get too much of either structure or entropy you’re in trouble - you reach to so-called critical complexity and your fragility increases. You become exposed and vulnerable. Your ability to absorb more uncertainty (and still function) diminishes, just as your capacity to face extreme events.
Images from Purestform.