On Debian, Fedora, etc, installing a package means letting it put files wherever it likes; which effectively gives the package author root on your system. Not a good base for sandboxing!

Also, they make it difficult to try out 3rd-party software, or to test newer versions of just some packages.

In 2003 I created 0install to address these problems, and Nix has very similar goals. - NixOS

• Fast, Declarative, Reproduble and Composable Developer Environments Using Nix (devenv) / HN
• Our Roadmap for Nix

see also

• Zero to Nix, an unofficial, opinionated, gentle introduction to Nix
• Crafting container images without Dockerfiles - I’ve been using Nix for this.