Jeffery Smith wrote:

This thread demonstrated just how fleeting PIMs are. Let's start with
Lotus Agenda, PackRat, Ecco, Ascend, Lotus Organizer, Desktop Set, and
DayTimer. This was followed by a geometric increase in apps, followed by
a geometric attrition rate that continues to this day. Now everything
seems to be going to cloud-based and subscription-based.

The longevity comes, once again, from big companies. MS Outlook is not my favourite PIM by any means, but I've been using it consistently for work at various employers since 2000. The Google equivalents probably do the same for many people.