Service areas were previously thought not to affect rankings for a Service Area Business, but recent tests have shown this to be a relevant ranking factor. While setting the service area historically had no influence on your Google local rankings, that has now changed.
Recent tests by SEO experts have seen that businesses that once were unaffected by listing a service area are now seeing a boost in their rankings by applying new target geographies. This does not mean that your local pest control should list itself as serving the entire continent however. It means that that for every functional service area of your business, whether it is just a downtown core or the entire general area of the city of operation, should be included on your listing.
All service area businesses should not more carefully curate where they list themselves as operating. Trying to cover absolutely everywhere that may be relevant is now spreading your search engine optimizations thin. Every business needs to update its Google Business Profile to focus around the area where they wish to rank. Businesses having themselves at the top of fewer more important services areas will go much farther than having middling rankings in geographies both relevant and not.