The ideal rule of Backups is “3, 2, 1. 3 Copies. 2 Mediums. 1 Off site”.
It requires quite a bit of work to make this happen for everything you care about.
In an ideal world your laptop or desktop would not contain anything of importance. You could delete it, and your Full Disk Encryption keys, at-will and nothing would be worse except maybe needing to re-download some things from remote servers.
However, it makes sense to keep some things around locally to work on them and while you’re working on them you may have the only copy of that data for a little while. Also while it might not “matter” if your laptop is wiped or destroyed having a recent backup is much easier to restore than to set everything back up again as it was.
The first backup to setup is File Backups. I currently use Arq on my macOS computers to create hourly backups into a cloud storage system (BackBlaze’s B2) and my NAS (via Minio).
You have other options too including
restic which provide basically the same thing but they’re a little more advanced. Arq has a cloud service, but I prefer to handle things myself.
B2 is insanely cheap. I pay roughly $12/year to store and access hourly backups dating back to 2017 for several computers. If you already pay for Google Drive, Dropbox, or etc. it’s probably smart to use those to store your backups just because 1) you’re probably not using all the space your have and 2) it’s already paying for it so however cheap B2 is doesn’t really matter unless you’re already using a lot of space up.
Using apps like Arq,
restic is really nice because they’re very simple designs.
restic are both open source and free (as in beer). Arq is not free or open source, but it is much easier to use and it’s design is very simple. Because they’re simple it means there are fewer moving parts for it to fail. They also encrypt your data locally so even if someone hacks your Dropbox no one can read through your backups. Services like BackBlaze’s unlimited back up service only make sense if you’re backing up insane amounts of data on a single computer. If it’s something less than actually 10TB of data then it may make sense to just use B2 directly instead.
The first backup for a macOS system should be done using Time Machine. For no other reason than it’s the thing which macOS supports the best.
Macs with T1/T2 chips it gets increasingly difficult to do disk image backups of. I used to simply go into recovery mode and create a DMG of the disk with everything.