Howard Oakley on eclecticlight.co:
Best practice for an M1 Mac is to ensure that it’s fully backed up, Data and external volumes only, to separable external storage. Should a problem arise which require Recovery, then it should be started up in primary Recovery mode. If necessary, it can then have its macOS container erased, a fresh copy installed, and migration performed from the backup. Cloning to or installing macOS on a backup disk serves no useful purpose, and just wastes 15 GB of space.
The rules have have changed. I’ve focused my backup workflow on cloud redundancy for files and photos. This breaks the 3-2-1 rule: 3 copies, in 2 devices, and 1 offsite. Having two different cloud copies, shouldn’t count. But given the changes in macOS — mostly SuperDuper, I got lazy.
No more, on my calendar is to have have my new backup strategy set by July 31st — a full 8 months before the next World Backup Day.