That is your choice in the world:
Energy is finite,
And you can use it for barricades
Either way, something will always
find a route around defences,
And you must discover a way to coexist
or be harvested alone.
This was more thinking out loud than anything else. The idea comes from plants, actually. They have two main methods of defence (physical things like thorns or chemical things like bad tastes or poisons), and energy expended on one isn't available to be used on the other. Prickly things often aren't (very) poisonous, and vice versa.
Extrapolate that to life in general, and... well, you get the idea. We all have our choices.