Lineage answers two questions that are otherwise expensive. Upstream: this number looks wrong, where did it come from and what touched it. Downstream: we are changing this field, what breaks. The second is impact analysis, and in organizations with any pipeline complexity it is the one that pays for the whole exercise — the alternative is a change freeze or a discovery in production.
In practice. Lineage is worth capturing at the granularity you will act on. Table-to-table lineage across the pipelines behind regulatory reports is usually enough to answer both questions; column-level lineage across the entire estate is a research project.
Where it goes wrong. Lineage is drawn by hand in a diagramming tool. It is accurate on the day it is drawn and wrong within a sprint, and because it looks authoritative people rely on it after it stops being true. Lineage that is not derived from the pipelines themselves has a shelf life measured in weeks.