St. James, Elaine. “Replacing Day Planner With Index Cards.” Los Angeles Times, June 8, 1998, sec. Business. https://www.latimes.com/archives/la-xpm-1998-jun-08-he-57703-story.html.

Apparently even with growing ubiquity of computers in 1998 and in a pre-internet era, syndicated (Universal Press Syndicate) productivity expert Elaine St. James suggested the use of index cards as a means of simplifying one's life, especially as compared with big and bulky planners and notebooks which predominated the timeperiod.

Notice that she specifically doesn't suggest "going back" to using index cards in the piece. Apparently the idea of that within the zeitgeist had been lost by this time.