You may be a very good writer who has a native command of the language. You may also be aware of professional writing styles and standards. However, all these skills are still insufficient to avoid the task of dissertation editing.
Even though a writer is honed, a dissertation will always need a review. There are innumerable aspects of language and presentation of content that it is simply not possible to take care of every minor thing while developing a dissertation.
All such linguistic and compliance aspects are considered by a professional editor. An academic editor can help you polish your language and ideas. This further makes your documents much improved, targeted, focused and reader-oriented.