Sure I also don't want to take away from what nix and even NixOS does do well, it is a great project and has many great ideas.

Also not sure you are aware (I think you probably are but I will state it any way) Nix != NixOS, and to complicate things further Nix it's self has many parts, it's a build system, a language, a package manager, enviornment profile manager (think like what python venv's provide) and kind of what ever you can make it do.

I will say Nix as a tool is a fantastic thing to have around and now with AI the wrangling and learning can become less painful but it does allow you to do a lot of cool things. Building Deterministically Deterministically building environments, integration tests/ setting up environments for such tests, more easily managing multiple possible builds for a project (well easier then wrangling make files or what ever directly and does provide nicer abstractions (not pain free) for building code). If nothing else give nix a try for building your next project and see what you think, very nice for setting up your dev env as well.

Personally I use something called flakes which is a way of managing a project and pinning it's deps. And this is one of the points things will break down and you will understand some of the issues. flakes are supported and used by many but also many reject them and the tooling is just kind of their and breaks some bits of nix. This aspect of different competing community standards is very very common in the nix world and is one of the major pain points.

> I worry that, since there are so few who truly understands the internals.

I have not filter it in that way but, I am not sure the issue lies with the lack of knowledge of the internals but nix seems to complicate things... a lot.

You have the nix daemon and nix store. Until you have good working knowledge of how nix works (not necessarily knowing the code I have only glanced at the internals of daemon and such and the more important aspect is actually the code written in the nix language generally). Don't touch store directly including trying to copy files manually between stores and such the daemon keeps a sql database of the entries and other things about the nix store means you should not directly touch it until you understand this and it's not intuitive or made to be understood easily.

>NixOS? Finally NixOS it's self is great especially at the start and once you get it but the whole idea is declarative configs and well I know have spent lots of time fighting this and while it does have escape hatches they can be obscure and confusing and error prone. An example of this might be something like llama-swap module, you configure your modules in nix and llama-swap will module will configure a systemd unit for you once enable it which sounds great but in truth you probably want to do things outside the config and make ad-hoc changes and you can set it up so all this is possible but you end up finding your self avoiding a lot of the declarative features and having to edit your config then build it and push it every time for things that are small can be very annoying.

The thing is though you can generally just tell it to use a path to your config or give it a config or even not cofigure a systemd unit at all, but many of these things stack up and you find your self fighting it a lot of the time. The default will have things like a firewall unit that pushes some 'useful' firewall rules that block listening and such and works with declarative configs to enable particular ports which is good, but if you don't know that you might spend a bit of time wondering what the hell is going on.

I would say if you still interested look first at nix tooling and nix and if you want to dip into the operating system you will understand a lot more about why things are the way they are and if you are someone who is finding they want to make a lot of quick ad-hoc changes to the system in question nix can get very annoying. The language is not great and difficult to learn, the main issue is that it's not typed and a lot of the features and right way to do things is arcane and occult, AI will help learning all this a lot though and bare in mind it's a lazy functional language.

Alpine for me is looking more attractive to build my host system on and still use nixos for some dev vms and other vms I use and configure Alpine in a well defined way but still lets me quickly hack a bash script into something. Again you can use nix it's self on any distro and even mac and windows (I think).