Wikidata is really good at is indicating where information can be found. You find 20 identifiers for Michelangelo to sources outside of the Wikimedia Foundation as well as the links to the 173 Wikipedias that have an article about him.
When we know how to link to these external source, we enable you to go directly to the page with the information about Mr di Lodovico Buonarroti Simoni. When we do not know how, like for the "BAV" (the Vatican Library) we just provide you with a number.
It is not unlikely that many more resources have information that is related to Michelangelo. If it is not information about the man himself, it is about the large body of work he has left us with.
At Commons you can find a lot of his work. When you drill down to the individual media files, it is not always obvious that the subject of an image is a work by Michelangelo. Sometimes you have to infer it from the title of a picture but it is much better when there is a reference to a template that indicates him as the "creator".
When Commons gets its update with Wikidata technology, these Creator templates will become really valuable; they will make it obvious who the creator of the object of a media file is.