Your customer just spent fifteen thousand dollars on something they will never climb up to inspect. They judged the entire job by the crew, the cleanup, and whether it leaks. When it's done and it holds, they feel relief, and relief does not write a Google review.
The next morning, life takes over. The new roof already feels normal. Leaving a review means sitting down and finding words for work they could not even see, so they mean to, and they do not.
Meanwhile every storm brings a wave of out-of-town crews knocking doors with the same pitch. A homeowner who got burned once reads the reviews obsessively. A bench of recent, specific, local reviews is the one thing that proves you are the real company that will still answer the phone when the warranty matters.