Interesting, I didn't realize that that was an option.As a fellow daily driver of NixOS, you’ve just summed up my biggest problem with it. You can do almost anything, and once you’ve figured out how and why you do it a certain way, that way often makes a lot of sense and the NixOS design can offer significant benefits compared to more traditional distros without much downside. But NixOS is out of the mainstream and its documentation is often less than ideal, so there is a steep learning curve that is relatively difficult to climb compared to a more conventional distro like Ubuntu.
The shared object problem in particular comes up so often, particularly if you use applications or programming languages with their own ecosystem and package management, that I feel like having nix-ld installed and activated by default with a selection of the most useful SOs available out of the box would be a significant benefit to new users. Or if including it in a default installation is a step too far, many users would probably benefit from some HOWTO-style documentation so they can learn early on that nix-ld exists, how it helps with software that was built for “typical” Linux distros, why you don’t need or want it when running software that was already built for NixOS such as the contents of nixpkgs, and how to work out which shared objects an application needs and how to find and install them for use with nix-ld.
I haven’t yet felt confident enough in my own NixOS knowledge to contribute something like that, but one nice thing about the NixOS community is that there are some genuine experts around who often pop up in these discussions to help the rest of us. I wonder if there’s scope for sponsoring some kind of “Big NixOS Documentation Project™” to fund a few of those experts to close some of those documentation gaps for the benefit of the whole community…