User blog comment:Sannse/Five Things Every Admin Should Know/@comment-1038387-20150710172004/@comment-5558012-20150710203951

WikiActivity is more visual (ie. images/videos are displayed when added to pages, the beginning of forum, blog, article, message wall comments are shown, shows categories added to pages, etc). This allows you to click less, and see common activity in more than a list display.

Yes, RecentChanges is very useful, but not everyone cares for that level of detail about the wiki.