Diagnose before you rewrite
The instinct is to refresh the page. That fixes one of four possible causes and wastes effort on the other three, so half an hour of diagnosis saves a week of writing.
1. The question is now answered without a click
If the page answered a simple informational question, the traffic may be gone permanently while the page still feeds the answer. That is traffic falling while enquiries hold, and the correct response is to check enquiries rather than rewrite.
2. Something technical broke
A redesign moved the URL, a no-index slipped in, or the content now renders only after scripts run. These produce sudden drops rather than gradual ones, and they are the standard redesign failure list.
A gradual decline is a content problem. A cliff is almost always a technical one.
3. A competitor published something better
Ask the engines the question and read what is cited now. If someone has a page with more specific facts and clearer structure, that is a content gap you can close — and the citation list tells you which.
4. The page went stale
Facts, prices, and examples that are no longer true make a page unusable as a source and occasionally harmful. This is what a stale-fact audit exists to catch before it costs you.
Then choose the response
Accept it and move on, fix the technical fault, deepen the content, or update the facts. Only two of the four involve writing, and picking the right one is most of the value.