Many of the freelance editing gigs advertised express requirements that indicate the hiring companies don't really understand what editing is. Or maybe I just take a narrow view of editing.
Editing concerns the improvement of content.
Editing differs from writing. Writers generate content. They conduct the research and write to convey the information and meaning. The editor makes sure that the content flows well, makes sense, and otherwise engages and informs the reader without undue confusion. Editing, therefore, employs a separate set of skills than writing. Editors are not fact checkers. Their knowledge is at once specialized and general: they understand the nuances of language and how best to exploit them. They need not possess the technical background relating to the topic under discussion.
That last part--the technical background--becomes more and more relevant to and required by hiring organizations. After all, someone could write absolute hogwash regarding crypto-currencies and I would know no differently. I could make sure that the hogwash employed a preponderance of active voice, minimized grammatical and syntactical errors, and generally made for interesting copy; however, I could not verify with any authority whatsoever that the information conveyed was factual and correct.
That said, too much of writing for business suffers from poor execution. Pick up a business report, any report, and count the number of passive verbs to active verbs. A preponderance of passive verbs leads to a deadly dull composition. A single, short declarative sentence surrounded by active voice makes a powerful statement. Declarative, state-of-being sentences strung together in succession have just the opposite effect.
Next, count the adverbs. Used sparingly, adverbs add illustrative detail. Overused, they make the narrative drag because they tell how something is done; they don't show it.
After that, look at the length of the paragraphs. Modern attention spans don't appreciate large blocks of text. People find them daunting and off-putting. Keep paragraphs short. That also ties into the longstanding advice regarding brevity. Mark Twain, Cicero, Alexander Pope, and others offered many pithy comments on the desirability of concise writing, all of which make very good sense. I particularly like this quotation from Hans Hoffman: “The ability to simplify means to eliminate the unnecessary so that the necessary may speak.”
Part of an editor's job is to cut out the unnecessary words and to determine the appropriate level of language for the intended audience. More than that, the editor looks to see whether each passage advances the narrative. Anything that does not has no place within the composition. Liken unnecessary words or extra scenes to the arbitrary addition of notes within music. Those notes don't enhance the tune, they detract from it.
Let your content sing. Hire an editor.