Many questions about genealogical topics should be regarded as "evergreen" -- a relative who has information about the person to share, or who wants to know more, may show up years later. In those cases, a response to an old question often has value.
It would, however, be nice to have an "old question" warning on threads about topics that are no longer current -- for example, a thread from 2016 that requested a technical improvement to WikiTree that was implemented in 2017, or a several-year-old thread about changes that where then being made at some other genealogy website.