Not only are the search engines promoting newer content but they are also (at least Google is) penalizing sites with “old” content [1]. Somewhat related, it’s outrageous to me when a university takes down a professor’s page when they are no longer employed or come up with a standard site for all faculty that is devoid of anything interesting, just boring bios.

[1] https://news.ycombinator.com/item?id=37068464