Provenance answers "where is this from." It captures the source material, the version of the model, and the transformations applied along the way.
Where traceability follows the path of reasoning, provenance certifies the origin of the material. The two work together. One shows how the answer was formed; the other shows what it was formed from.
Strong provenance lets an organisation distinguish grounded output from invention, and current sources from stale ones. It is the foundation for trust in any knowledge-driven system.