A search engine does not know how old the contents of a page are. They'd have to diff different versions of a page, which is not foolproof; for html it's particularly noisy compared to, say, code. Even when that strategy works, or when there's only one version of a page, it's only possible to determine when the search engine first saw a piece of content, not when that piece of content was created.

In contrast, things on a credit history are dated.