Render projects down to stems, backup on more than one device and refresh those backups ( copy to a new drive) from time to time (every x years)
That is called archiving strategy, every one should have one, and there are a lot of them.
The real die hard approach would be doubling up on all hardware too.
As technology advances it would probably be wise to save to new digital formats when they become available.
Maybe no one is using PCM in 10 years ?
Not saying I’m doing all that, but it is important to think about and come up with a strategy that is affordable and does not take too much effort, or they will be put off to “later” or never implemented.
My personal approach is, Render mix and stems to project folder when done. My project folders get automatically backup every day to a NAS that every night does a backup to another NAS. My first NAS is set up to dump/copy it’s content if a big enough drive is connected to its USB port. When I remember I store one of these usb drives at a friends place, well we swap drives.