It seems "usage" is often used in the sense of "(toughtful) application", i.e. employing something wisely and selectively to fit the need.
"use" seems simpler in its meaning, similar to "utilization" which means employing something for a useful purpose in a way that doesn't require much thought or skill.
For example:
1. The adjective-like usage of a noun before another noun seems universal across languages.
2. The use of wood as fuel has been steadily declining.