Search Engine Optimization is a skill that is constantly changing and evolving. If you work in this profession, then resting on your laurels and sticking with what you know simply isn't an option any more.
It was only a few years ago that we believed the best way to succeed at SEO was to stuff a page full of keywords and to pay for links from as many sites as possible. Of course, we know that this will get a site penalized and even de-indexed pretty quickly these days!
Today, Google is an AI-driven company. Google wants to combine its search engine with its smart assistant, so that you can simply ask Google who was in X film, or how to cook X meal, and it will be able to answer in natural language by pulling from the web.