Earlier quoted context omitted.
Bootable snapshots are a thing, also known as boot environments. You need to use ZFS or btrfs, or possibly bcachefs or LVM offer them. And they never have seemed to have a great implementation on Linux compared FreeBSD, but they do exist.
> but they do exist. And here's the crux of it, isn't it? Unless it's accessible and enabled by default, it might as well not exist from the PoV of the end user. Windows' restore points happen automatically before updates or driver updates. Then you're prompted automatically to restore if Windows fails to boot after an update. As usual Linux has all the pieces but no desire to create UX to go with it. Which is a sham…
For what it's worth, at one point Ubuntu supported installing on ZFS through its regular installer and installed the boot environment thingy, with a snapshot before every update. I have one such machine which is now running 23.04 and that still works. I've never had to use in practice, though.