The problem it removes is configuration drift — the gradual divergence between environments caused by manual fixes nobody recorded. When staging and production are built from the same definition, "it worked in staging" becomes a meaningful statement rather than a coincidence.
It also converts disaster recovery from a document into an executable. Rebuilding an environment becomes running a definition rather than following a runbook written by someone who has since left. The discipline required is that manual changes must stop entirely — one hand-edited resource reintroduces exactly the drift the practice exists to prevent.
Codazz builds this in production — Infrastructure as Code.