Search Engine Optimization or SEO has certainly not faded out with time because SEO is going to exist as long as search engines search for websites. There are many myths about SEO which are incorrect and must be rejected with facts. wpvortex.com/articles/seo-zombie-will-never-die/ brings such facts to light and have been discussed here.
Knowledge of search engines
SEO cannot be attempted without proper knowledge of the operations of the search engines as widely believed. The search engines like Google crawl and index websites which form the basis of SEO. Thus, SEO can never be understood without the right knowledge about crawling and indexing. The concept of algorithm updates of search engines such as Google often create doubts in the mind of the people. This is baseless because crawling and indexing of websites are always done by the search engines regardless of the algorithm.
Understanding of codes
People with little or no knowledge of codes such as HTML, PHP, CSS or any other language cannot attempt SEO all by themselves. This is because the search engines decipher the codes of the websites and store them for relevant searches. The URL structure, images, alt tags and many other aspects of the code are important. Thus, it is clear that SEO means building the website in the correct way which enables Google and other search engines to pick it up.
WordPress theme is said to be the most SEO friendly CMS. This is not entirely correct because WordPress themes may or may not be SEO friendly. The key is to pick the right theme.
SEO with plugins
SEO plugins for WordPress websites are useful as they make those tasks easy which are done by coding. However, without a complete understanding of SEO, one cannot run the plugin to determine whether it works or not.
The above points as put forward in wpvortex.com Why SEO is a Zombie and Will Never Die prove that amateurs should not do SEO themselves and must hire professionals.