I am looking at the edit history of a number of major articles on
historical topics (in the English Wikipedia)
I find that most of the important writing was done in 2006-8.
Typically, the article reached maturity about 2008 and since then the
rate of editing has plunged. In most cases I see only minor or
maintenance editing since then. The new material since 2008 is
mostly cosmetic: illustrations still get added, lots of links are
made, new categories added, new lists are appended, vandalism is
removed. The citations are increasingly out of date. The articles
are long in tooth.
Wiki is now resembling the old paper encyclopedias--they would get
old fast and need constant updating either through yearbooks or new editions.
Richard Jensen