Configuration management. A few years ago, I timed myself doing a full reinstall on my private notebook to switch to a different partition layout. I was done i

Configuration management. A few years ago, I timed myself doing a full reinstall on my private notebook to switch to a different partition layout. I was done in 30 minutes, of which most of the time was spent waiting for packages to download and install and for the /home backup to restore. Without configuration management, this would have been a full day of work just installing stuff and figuring out things like "how do you enable palm detection on that touchpad model again".