The other power
A significant driving force for me to upgrade has been electric power consumption. Power consumption in a upper-mid level desktop system has fallen from around 600W to about 60W in the past 20 years. That's of no concern if you live someplace cold, but screw that in a hot climate. I'm hoping the year 2020 is the last year I need to buy a spinning rust array too. That's about 8W/disk that's always on, with one extra for RAID5 reliability, and then double it because I need a backup.