I like the idea of the fedora immutable distros, but the reliance on flatpak makes me a bit nervous (guess I’m just old-fashioned)… I think some kind of solution that puts a stable system like Debian or immutable fedora with a package manager like Nix might be very good (I know the U-Blue guys have been playing with homebrew?)
You can still install Nix (package manager) on Atomic, on uBlue, it even comes pre-installed afaik.
And also, there’s Distrobox, which is totally enough if you prefer package managers over Flatpaks.
I personally like the “reliance” on Flatpaks. I think it reduces the fragmentation and makes it easier for devs, but that’s just my opinion. Do as you prefer.
Actually, I just tried both homebrew and Nix with a Debian 12 installation and I’m not impressed. Homebrew only ships CLI apps, and GUI applications installed with Nix famously don’t show up in application launchers… it seems like you don’t really get the features of Nix unless you use NixOS.