In the current days, writing has become a business and a huge one so to say. With Amazon, and such other bookstores, websites, blogs, medium, and other publishing platforms. It's no denial that writing has become an honest career for most creative peoples. Perhaps a side job for people passionate about it and also an ultimate tool for online selling.
With that said, writing has shifted from passion to a business. In that, anyone can write and sell their content regardless of whether they have the integrity and ability to write well. That is to mean that, it does not matter anymore whether you are good at writing, grammar, and spelling or are flawless about it. If you are willing and have the content, you can still publish your content and have it selling eve on highest platforms. All you have to do is write your content down at your very best understanding then hire someone to streamline the rest. With editors and proofreaders all over, your accuracy is nothing to stop you from making some extra dollars from writing any more.
Again even the best writers have flaws I believe, and even if their work may look outstanding to many, they too need to be fine-tuned and adjusted at some point. Even, the best writers and publishing companies have editors to go through the work to review it, correct errors, inconsistency, accuracy, and omissions. Again it's of prime importance to have someone else go through your work other than you. It increases accuracy and adds value too. Sometimes you can't notice even the gravest mistakes of your own work. There are chances that one after reading your work can present it in a better approach than you do without changing its meaning or introducing more errors.
View website for more details about copy editors: https://www.huffingtonpost.com/brooke-warner/editorial-services-explai_b_8039172.html.
There are people, a lot of them who are dedicated to doing that work. Companies too are out there whose prime focus is to turn a manuscript into a mind caching and convincing book. They are professionals, who are well experienced and have the best resources and tools to make you work amazing. Of course, they are native English speakers' maybe but have grammar at the back of their palm and would not let a word pass unnoticed.
Getting a copy editor today is always a click away. Actually, the distance between you and your next editor is the internet. A simple typing of the word "copy editor" on a search engine pulls out a whole lot of legit and credited copy editors and companies that will leave you in paralysis for choice.