If I’m understanding the question right. This is what Immutable Linux distros do. Such as Nixos, fedora silver blue, and vanilla os.
I use nixos myself. But its quite different then most distros. The way you config it and install packages. For the better in my opinion.
Something like silverblue works pretty much the same as normal Fedora except you can’t install packages like you normally would. Because the system files can’t be edited. You mostly use flatpak for everything. Except the system updates. Which you have to reboot to switch to the new updated image. But past images are saved so you can rollback if needed.
From what I understand Chromebook os is a Immutable Linux distro same as the ones I mentioned. Just with Google with built in.
There is a file system you can use. A alternative to ext4. I think its Btrfs. I never tried it. But it let’s you take snapshots that you can restore to. That’s not just system files but everything. And pretty sure you can use it with a disto like arch and Debian. I think that’s how snapshots work. But as I said I never actually tried it out.