Is installing a package as simple as $ nix install vscode ? And would it “just work”?

You fool. You absolute buffoon. You're doing it wrong. That's the wrong command, and even if it was the right command, this method could cause issues down the road. It goes against the declarative philosophy of nix. You're supposed to refer to packages by their attribute, rather than name. If you launch the installed app that way, it won't have any hardware accererated graphics becuase hardware accelerated graphics are impure, don't you know this?

You need to read the nonexistent documentation to find all of this out, and then select a declarative solution, like home manager or nix-shell or nix develop, to install software, and nixgl to get hardware accelerated graphics for nix packages on non nix systems.

(/s (ish) over)

Yeah. Nix has some issues. If you just want more packages available, I would recommend distrobox.

It's a very powerful tool, and I use nix to manage all of my development environments, but it has some severe limitations that only have hacky workarounds. I could not get hardware accelerated nix packages to have a working dekstop entry. So instead, I have to type nixGLIntel gzdoom in my terminal when I want to play doom.

In addition to that, the documentation is very poor.

The other comments in this thread elaborate on these, and a few other issues.

I mean, yeah, it's nix profile install nixpkgs#vscode and it should kinda work. Although to run it, you might have to also do nix profile install github:nix-community/nixgl --impure and then run vscode as nixGL code because of video driver awfulness.