Absolutely, and if it was not clear from the context, I call it a trap because that feels like what I'd fallen into at some point. Let me see if I can describe it better.

The Nix ecosystem is attractive to me at a high level because it looks like it has the possibility to revolutionize a lot of the problems that come up with an increased focus on devops culture. The problem with the Nix ecosystem itself is that it is larger and more varied than it might appear.

There are really three large entities in the ecosystem: nix the language, nix the package manager (nixpkgs), and nix the OS (NixOS). Despite the fact that there is a lot of overlap in some of the details of these three things, they are easily understood as separate entities. There are a bunch of smaller secondary entities such as nix-darwin, home-manager, devshell, and digga (formerly devos). The aim of these entities is usually to supplement, enhance, replace, or reproduce features of nixpkgs and/or NixOS.

Each of these entities has its own learning curve. It takes surprisingly little nix knowledge to use it as a dev environment generator, but nixpkgs knowledge will help a bit more. Even within nixpkgs itself, each major language has a large ecosystem built up around facilitating package building and deployment, and these are extremely heterogeneous. Some of them require that you regenerate the entire matrix of package dependencies for the package manager (javascript, haskell). Some of them have tooling that allow you to get started with almost no effort (mach-nix for python). These all have their own peculiarities. NixOS has a ton of modules, all rather heterogeneous, on top of requiring more careful knowledge of how to put together a system than most other distros. And nix the language without nixpkgs is very small, and some of what it does have built in is necessary so it can bootstrap an actual stdlib from nixpkgs.

The trap is sprung once you've been sold on the idea, and even seen it shine through some things, but feel like you have an entire wall to climb to get to a point of general competency. All of these things I've described, and even some of their subgroups, require new knowledge for a more complete understanding. I do not understand the details of many of the things I have described, and I would consider myself a power user at this point. What looks like one gigantic, insurmountable cliff is really dozens of much smaller cliffs, many of which are not necessary, at least not to most people.

At one point I wanted to test my skills in a really generic way, so I helped fix broken packages on macOS during one of the two yearly regression periods where the community tries to get the CI builds passing. I picked the packages completely at random. Most of what I ended up fixing was C/C++ based, and I don't normally work in it, or I haven't for many years, but I feel like I learned a good bit about cmake. I don't really write Haskell, but I was able to fix a bug in a solving library having to do with a missing portability shim. I didn't have help for any of this, and in some cases I was either too stuck to fix the build or unable to fix it due to problems beyond my control.

All of this is to say that I think getting to this point is a lot less painful if one takes a use case, preferably a narrow one, and focuses on learning whatever is necessary in the service of that use case. Some good topics are dev environments, using nix as an app/project builder, using nix to build containers, using nix to manage remote machines (the difference between these and personal machines is that the scope of these machines tends to be much smaller). I think people try to take on too many of these things simultaneously and end up overwhelmed. That's not to say that NixOS isn't worth learning, but I think many people could realize most or all of the real-world benefit if they use nix on an OS they're comfortable with. Coming back to my comparison of being dropped in the Romanian countryside, if you want to learn Romanian, start there. If you want to experience the countryside, maybe a guided tour is the way to go. If you want to learn about the life of Ligeti, you might not even need to learn Romanian! But total immersion is difficult and draining, and a failed immersion experience doesn't mean Romania is a bad place. So it is with Nix.