How Crucial Are Professional Editing Services for Authors?

During a local writing meetup, an author shared how Houston Book Publisher connected them with professional editing services, transforming their rough draft into a polished manuscript. Hearing their story made me wonder about the unseen impact of editors on a book’s success. Do these services merely correct errors, or do they shape the narrative, tone, and voice in ways that define a book’s reception? How much influence should editors have over the author’s original vision?