In all probability, when one says SEO, Google naturally comes to mind. Google at infancy stage had to quickly keep pace with SEO "experts" who started implementing "black hat" techniques to cheat the system. Google had to deal with content spinning and link spamming at the beginning of their journey. However, content and link spamming are only part of "black hat" techniques used by experts at the beginning. There are many today though 

Article spinning: Content writers used to write a good article and when the started doing well on SERPS the SEO experts used to edit the article or rephrase it to "cheat" google and use it repeatedly

Link spamming : Getting links from irrelevant sites just to take advantage of PR(Page Rank). Buying links by black hat experts was another challenge genuine SEO experts.

With above techniques giving way to other "black hat" techniques Google had to focus their efforts on developing fool-proof algorithms so that any techniques employed to cheat the system couldn’t survive. Effective Google algorithms started taking shape in form of Penguin algorithm in April 2012 sought to fight spam in search results and with subsequent and frequent updates Google has almost ensured that "Black Hat experts" are wiped out of SEO business

How does Google regular updates benefit SEO?

Regular Google updates has in fact made sure that one has to really "study" and "understand" to become a SEO expert. These updates have also ensured that SEO is a skill craft and only experts can provide real value for money to their clients’ businesses.

Since it is not possible to cheat Google anymore the new/old website owners are getting the best expert advise from service providers. The regular Google updates have also ensured that one set of team cannot handle the complete SEO process which includes developing SEO friendly website, off-page, on-page, content writing, Social media promotions etc.,

Experts who realized this started acquiring skill sets in 1 or 2 skills and started partnering with competitors who have different skill sets. This also ensured that everyone involved in SEO business were getting benefits directly or indirectly. Today PR, digital, advertising or content experts have to work together with SEO professionals so that combined efforts produce desired results

With every update since 2012 Google’s focus was to serve up good quality, relevant sites to users. Google successfully evolved the SEO from how to cheat to a holistic process that contains good content development, relevance targeting and building genuine online credibility in the right way.

SEO is here to stay

Few years ago some "experts" have started predicting the death of SEO business but SEO is here to stay it has made several technological advancement, it is evolving rapidly and becoming more sophisticated. SEO should be seen as an indispensable marketing tool and should not be seen as a separate factor to other marketing disciplines. AS long as new websites keep coming up SEO experts become more and more busy with their existing clients and new business opportunities.