There is a similar question on the site which must not be named.
My question still has a little different spin:
It seems to me that one of the biggest selling points of Nix is basically infrastructure as code. (Of course being immutable etc. is nice by itself.)
I wonder now, how big the delta is for people like me: All my desktops/servers are based on Debian stable with heavy customization, but 100% automated via Ansible. It seems to me, that a lot of the vocal Nix user (fans) switched from a pet desktop and discover IaC via Nix, and that they are in the end raving about IaC (which Nix might or might not be a good vehicle for).
When I gave Silverblue a try, I totally loved it, but then to configure it for my needs, I basically would have needed to configure the host system, some containers and overlays to replicate my Debian setup, so for me it seemed like too much effort to arrive nearly at where I started. (And of course I can use distrobox/podman and have containerized environments on Debian w/o trouble.)
Am I missing something?
Well maybe you youself are too new to recognize some of the appeals ;)
One large advantage with silverblue is, that the whole composition of the OS does not take place on the target machine. That means that all the issues that could arise will not take place on the target machine, and can be dealt with beforehand. In the simple case this could mean just enjoying vanilla silverblue without having to think about possibly borking the machine. In an advanced usecase this could mean for example building the os images in a GitLab CI/CD pipeline (with well working tooling that exists already for docker etc), then having automatic tests in the pipeline ensure that everything important works as expected. And only if the tests pass, the image will be added to the repositorie’s image registry, where the target machines will fetch it from automatically and rebase to it.
No, I fully understand it. But if you build the whole system where every package is isolated, none of the packages interfere with each other, and every package is tested across a wide array of architectures, you can just as safely put together your ideal OS setup and don’t have to deal with being locked into very simple and bare system.
The right place for immutable OSes is if you’re using it as a server for container workloads, where you will never customize the base system. Or if you never want to customize your system. Yes, you can customize the system image, but it breaks all the guarantees that the images gives you because the packages themselves are not isolated and by bumping a wrong dependency for a custom packages you can still break the whole system.