When I was testing out nix, and while it is more flexible and powerful, I ended up with a system that is pretty similar to how the atomic distros work.

I would essentially have a stable custom system, and then install everything I could at the user level with home-manager, which I think is best practice? It's annoying to have to rebuild everything when you install at the system level, anyway.

The atomics operate in a similar way. There is the system layer, which is basically a docker container, and then a user layer where you install whatever via flatpaks for gui's, homebrew for cli's, distrobox for anything not on either, or layering for programs that need system level access to work properly.

You can customize the base installation similar to how you can with nix, but instead of using the nix language it's customized like you could with a docker container. The biggest difference is that it's harder to customize the system layer because it requires github (although I think people have been able to do a self-hosted setup), and there is no nix-language equivalent for the config files.

Both are stable, and both allow you to fall back to a working setup if you bork something.

Both encourage containerized workflows, although nix can do that in a unique way with dev environments per directory.

In the end the atomic distros like bazzite set up everything close enough to how I would personally that it wasn't worth messing around with nix.

The atomics are immutable, so you have to layer the packages on your base image. It's not fully the same as NixOS, but it's functionally similar since the OS is imaged every time you install something.