A backup is a prime requirement.
Trouble is with many power supplies they exist as long lost echoes of something that you had many years ago and have long discarded. (I mean, you don't throw away something that works fine ... right ?)
So now these black beetles with their long tails lurk everywhere providing dc voltages from 3 through 30 volts. They've already filled drawers and shelves with their sinister presence,
"and slowly and surely draw their plans against us."
