If you were considering designing and building your own home, you would hire professional tradespeople to take care of the project, unless you were an expert in the building trade. Trying to project manage the building of a house, with all the complexities, without any experience or knowledge would be a complete disaster. Even if you are using competent builders and craftsmen, you would expect them to be skilled in their trade in order to build a high quality home.
Although many people take great care to ensure that only skilled trades people carry out work in their homes or undertake projects, many are happy to undertake the Search Engine Optimisation of their website themselves, although they do not have the required knowledge. If SEO was a simple task which could be self-taught, all business owners would perform the SEO themselves. SEO copywriters have the relevant knowledge and ability to create original articles and web copy for your website, which help to increase the ranking of your website in various search engines.
A website for a business will not be discovered by the public unless it has been optimised, which requires skill and knowledge. The production of web content and articles which have been optimised for the search engines has been proven to increase web visitors and return on investment. However, just as you wouldn’t consider allowing an unskilled person to build your new home, or even carry out repairs for you, a professional writer will have the necessary knowledge and language skills to create content for your website.