Author Rank means your reputation as a content creator which will directly influence your Page Rank with in Google search results. Each content provider has their work graded, and it’s these grades that Google will use as information about how useful one’s content is within the Google search engine.
Good quality content is one of the most important factor for drawing attention and traffic to a website. Content is no longer based solely on the authority of a domain or Web page. It is increasingly based on the reputation and authority of the individual who authored the content.
Good Content + PR Rankings + Author Rank = Better Results
Now Google has stopped supporting it and asks webmasters to focus on https://developers.google.com/search/docs/guides/intro-structured-data