User blog comment:SEOkitten/Search Suggest, Trends, and Content Coverage/@comment-4632631-20150901115116/@comment-5973717-20150901183857

Better SEO makes it easier for search engines to understand your wiki. When search engines understand your wiki, they're more likely to increase the page rankings of your wiki's pages. With higher ranks, you will get more people coming to your wiki. This means you will get more contributors and readers, who in chain improve your wiki's content.

In summary, better SEO - > better content.