Am I the only one using Btrfs snapshots like this?

i prefer nix-shell -p or distrobox

You are making it unnecessarily difficult for yourself. Rolling back a snapshot that you made before the intentional messing around is less effort than rebooting twice for seemingly no reason. Booting into a snapshot is not sandboxing, it's not an added layer of security against a malicious package.

"Except when something breaks after an odd update once or twice per year"

You don't need snapshots, except for the moments when you do. The point of snapshots is that they're so cheap that you can let them roll on their own and only care about them the day your system breaks.

You can do (most) of this without rebooting by leveraging the btrfs support built into systemd-nspawn, which allows creating ephemeral data volumes to mess around in. It's meant for containers, not the semi-Silverblue system you've set up, but it may save you time messing about with new tooling.

It should also be noted that although tools often miss support for it, almost any LVM2 filesystem can do snapshots if set up with enough free disk space for them.

I just use a package manager hook to set up btrfs timeshift snapshots whenever I do something to the root partition, but to each their own.

You’re not alone. I do use snapshots for failure protection but I also use it when I know I’m likely to induce a failure by running an experiment.

It’s also just as valid to not use the snapshot feature at all. Perhaps you value data integrity, for example, through the use of full checksums enabled by the design.

Your system and the software it runs belongs to you and is in your service.

I've done that before when debugging system issues. Create a snapshot before and after the issue, and diff the files to see what changed.

I also took a snapshot before updating to a new version of Mint, realised it broke a bunch of stuff and rolled back.

Honestly, I wish btrfs was the default in many places since taking a snapshot is so cheap and easy.

Why not do both?

I use a script in cron that uses timestamps as snapshot names, and deletes old ones. Then I also take a snapshot with a timestamp right before doing anything dumb.

You could even make a script called mksnap that figures out what zfs/btfs you're in on the current folder and auto-snaps it.

You restart and reboot into the snapshot? Maybe KVM and ssh into it could be a nicer workflow?

+1, I do the same.

That sounds fine, but isn't this also what LXC is for?

This is precisely what Opensuse MicroOS, Aeon, etc do, with the one difference that they use the snapshots as a fallback rather than a test env.

I'm not using btrfs on my main workstation, but I make a fresh backup whenever my distro prompts me to update. I haven't needed a backup in years though, because I'm experienced in doing even experimental things the way they should be done (like not using sudo in reflex for any permission error or using /usr/local/ or .local/ instead of mixing custom stuff with OS stuff etc)

I wrote snapshot hooks for Arch that fire before installing or upgrading packages and I have a simple shell alias that I can use to fire off a manual snapshot any time I need one. If a package breaks in an inconvenient way and can't just be dowgraded back to function or I have some other time pressure I can just point my root partition at a clone of my most recent snapshot and reboot to roll back. I don't usually bother rebooting into a cloned snapshot to test changes as I can just perform the same steps to roll back and the automated rolling snapshots mean I don't need to baby anything to have the same protection.

You can still do the auto snapshot daily/weekly plus the manual snapshot whenever big update coming or try something.

I do not use snapshots despite using BTRFS due to low disk space

I also don't use my brakes too, because my car has an airbag