Search Console is the only place you can see what people typed before they found you, rather than what you assume they typed. That gap is usually where the opportunity is: pages ranking just below the fold for a term worth having, queries bringing impressions but no clicks because the title does not match the intent, and phrases you never thought to target. It is also the first place a problem shows up — pages dropping out of the index, mobile usability warnings, a page blocked by accident after a site change. We check it regularly rather than only when traffic falls, because by the time a drop is visible in your analytics the cause is often weeks old and harder to trace.