Maybe if you use buildUserFHS and --impure a lot. But NodeJS applications that try to download binaries at install time or python packages with conflicting package versions definitely take more than a minute or two. Just look at the history of Anki in Nixpkgs, or the derivations for JetBrains products or Cypress or any of the other packages that took consistent effort by multiple contributors to even get them working in the first place.
I think it's important to manage expectations about Nix and that includes being realistic about what's easy and simple what isn't.
I think it's important to manage expectations about Nix and that includes being realistic about what's easy and simple what isn't.