That’s generally a good idea, however, there can be reasons not to do it.
The device could be infected in a way that it won’t turn on again.
You might have an isolated management network that allows you to monitor the device and traffic (naturally ripping all cables also disconnects the management network).
And whatnot. But generally I agree.
I think that’s rather odd comment. Naturally nobody wants ransomware. And there are good reasons.
Backups may exist, but do they work properly? Or are the backups encrypted too?
How old are the backups? They might be less than a day old. But less than a day might still mean a lot of extra work and financial loss.
There might be a lot of work restoring the backups. You might have a lot of different systems.
In one of the largest ransomware cases in history, Maersk worked for months to get systems back up and running and data up to date. The insurance payout for it was 1,4 billions. Which is at least indicative of the cost.
And Maersk had recent and working backups.