I’ve been running Bazzite for months and I have extremely happy with it. I switched from Windows and only use Windows for SteamVR now. I use atomic distros almost exclusively now.
If you like to customize and tweak everything about your OS than an atomic distro probably isn’t for you. You probably want something like Arch.
If you need/want an OS that is incredibly reliable at the cost of disk space and customization, than an atomic distro might be for you. The main thing an atomic distro provides that a traditional one can’t is reproducibility. Since the distro is a base image with packages layered on top you should be able to repeat those steps and arrive at the exactly same image. The system partition is then made immutable so that it stays in this reproducible state. This prevents users modifying system files and creating a unique system that can’t be reproduced. This should make bugs easier to track down because each install of the distro is always identical. You can still add packages by layering them on top (think of each package you layer as another “step” in the image build process. By tracking the steps you have added it keeps the image reproducible). Its pretty similar to how a dockerfile works.
Bazzite also keeps the previous version of the OS, so if an update fails you still have a working computer. Like others have said you can create snapshots on traditional distros so this isn’t really a unique feature, but it is nice it has it by default. I swear Bazzite also used to have A/B partitions as well which is really nice if your OS somehow gets corrupted, but my computer doesn’t seem to have them anymore.
The other nice thing about an atomic OS is because it locks down your system partition the main way to install applications is either flatpaks or appimages. These use more disk space but should always have the correct dependencies (which fixes another whole class of errors). You can also use flatpaks or appimages on a traditional distro but an atomic one enforces it. If you can’t install an application as a flatpak or appimage you can use package layering or distrobox to install it. Distrobox allows you to have a traditional distro in a container and integrate its applications into your main atomic OS. If something goes wrong with the container you can delete it and rebuild it without affecting your OS. You can also have a different container for each app so if something happens to one container you don’t lose all of your distrobox apps. Also something you could do on a traditional distro but don’t need to.
All of this leads to a really stable base os and the main advantage of an atomic OS: You should always be able to boot your computer. The downside is everything you install needs to be in a container so that if it causes an issue it doesn’t affect your base os booting.
This reminds me of Proxmox and how you really shouldn’t modify the host because you risk making your system unbootable and jeopardizing your containers and vms. Its much safer to have a stable, solid base and do riskier stuff in container or vm that can fail and be rebuilt. Proxmox would actually probably be a good candidate for an atomic distribution.
I’ve always heard this as “You can lead a horse to water but you can’t force it to drink”