Most security policies live in documents. They’re written once, reviewed annually, and ignored daily. Engineers learn to work around them or wait for approval that never comes.
Policy-as-code changes the contract. Instead of describing what should happen, you encode what must happen. The policy becomes infrastructure: versioned, tested, and automatically enforced.
This only works when policies are written by people who understand the systems they govern. A policy that blocks legitimate work gets disabled. A policy that makes the secure path the easiest path gets adopted.